Practicing with Maths Mela Class 5 Solutions Chapter 3 Angles as Turns Question Answer NCERT Solutions improves a student’s confidence in the subject.
Class 5 Maths Chapter 3 Angles as Turns Question Answer Solutions
Angles as Turns Class 5 Maths Solutions
Class 5 Maths Chapter 3 Solutions
NCERT Pg 32-33
Question 1.
(i) Can you recognise the child in the picture who has made a full turn? Who has made a half turn? How do you know? Discuss in class.
(ii) Give examples of real-life situations where you observe turns.
Answer:
(i) Yes, I recognise the child in the picture, child C has made a full turn and child A has made a half turn because in a half turn, the person faces the opposite direction and in a full turn, the person comes back to the original position.
(ii) (a) The minute hand of a clock making a full turn in 1 hour.
(b) When driving, you turn the steering wheel to change direction.
(c) Turning a key in a lock.
(d) Dancer making a quarter, half or full turns.
Question 2.
A giant wheel makes a full turn when it comes back to the starting position E.
(i) Reema takes two half turns in the same direction.
It is like a ………. turn.
(ii) What happens if she takes 2 quarter turns in the same direction?
It is like a ………. turn.
(iii) What happens if she takes 4 quarter turns in the same direction?
It is like a ………. turn.
Answer:
(i) Reema takes two half turns in the same direction. It is like a full turn.
(ii) If she takes 2 quarter turns in the same direction. It is like a half turn.
(iii) If she takes 4 quarter turns in the same direction. It is like a full turn.
Question 3.
Write some of the everyday objects that involve turns. For example, taps,
………., ………., ………. , ………. and ………. .
Answer:
The examples of the everyday objects that involve turns like taps, doorknobs, wheels, clock hands, scissors and fan blades.
Question 4.
(i) What is the maximum possible turn in each of these cases? Check and tick.
(ii) Do any of the above objects make a half turn? Write their names below
_________________________
(iii) Do any of the above objects make a full turn? Write their names below
_________________________
Answer:
(i) (a) The maximum possible turn in clothes clip is less than a \(\frac{1}{4}\) turn.
(b) The maximum possible turn in door with hinge is more than a \(\frac{1}{4}\) turn.
(c) The maximum possible turn in tongs is less than a \(\frac{1}{4}\) turn.
(d) The maximum possible turn in scissors is less than a \(\frac{1}{4}\) turn.
(e) The maximum possible turn in file cover is more than a \(\frac{1}{4}\) turn.
(ii) Objects that make a half turn are door with hinge and file cover.
(iii) None of the above objects make a full turn.
Let Us Do (NCERT Pg 34-36)
Question 5.
(i) (a) Making a paper fan. Take a rectangular paper, fold every 2 cm as shown in the picture. Paste ice-cream sticks as shown below to create a paper fan.
Answer:
Do yourself.
(b) Use your paper fan to show different acute and obtuse angles.
Answer:
Do yourself.
(c) Let us look at the turns made by the paper fan, keeping one side fixed.
Make an acute turn with the straws or fan. Continue to make another acute turn. Can the two acute turns together make another acute turn?
Answer:
Do yourself.
Yes, two acute turns can together make another acute turn but not for always.
(ii) You might have built houses using the hard cover of notebooks or cardboard pieces.
Look at the angles marked in the house. What angles are you able to see in this house?
Write your answers as right, acute or obtuse angle.
A: ________
B: ________
C: ________
D: ________
E: ________
F: ________
G: ________
H: ________
Answer:
I am able to see acute, right and obtuse angles in this house as A, B, C, D, E, F, G, and H.
A. Obtuse angle
B. Right angle
C. Acute angle
D. Acute angle
E. Acute angle
F. Right angle
H. Right angle
G. Obtuse angle
(iii) Make a 5-sided shape with 2 right angles, 2 obtuse angles and 1 acute angle in your notebook.
Answer:
In the above diagram, 2 right angles at points A and B, 2 obtuse angles at points C and E and 1 acute angle at point D.
(iv) Look at the angle formation between the legs of these gymnasts.
Identify whether the angles are acute, obtuse, right or straight.
Answer:
Answer:
(a) The legs form an acute angle.
(b) The legs form a right angle.
(c) The legs form an obtuse angle.
(d) The legs form an obtuse angle
(e) The legs are in a straight line, forming a straight angle.
Angle Measuring Tool (NCERT Pg 36)
Question 6.
Let us make our tool to measure turns.
(i) Cut out a circle from a tracing paper and fold it to make 8 equal parts.
Attach a straw to the centre and mark the starting point as shown.
(ii) Try this.
(a) Show a \(\frac{1}{8}\) turn of the straw.
(b) Show a \(\frac{2}{8}\) turn. Show a \(\frac{1}{4}\) turn. Show a \(\frac{3}{8}\) turn.
(c) What angle have you made with a \(\frac{2}{8}\) turn? A \(\frac{1}{8}\) turn is half of a quarter turn.
(d) What angle have you made with a \(\frac{4}{8}\) turn?
(e) Continue turning by \(\frac{5}{8}\), \(\frac{6}{8}\), \(\frac{7}{8}\), and \(\frac{8}{8}\). Check when you have completed a \(\frac{3}{4}\) turn and a full turn.
(f) Now, cut out \(\frac{1}{8}\) and \(\frac{2}{8}\) parts of the circle and paste them on a thicker paper or board. Use these as angle measuring tools.
Answer:
(i) Do yourself
(ii) (a) A \(\frac{1}{8}\) turn of the straw means rotating the straw by one part of the circle.
Since, the circle is divided into 8 equal parts, therefore each part represents \(\frac{1}{8}\) of a full turn.
(b) A \(\frac{2}{8}\) turn is equivalent to two out of eight euqal parts of the circle.
A \(\frac{1}{4}\) turn is equivalent to \(\frac{2}{8}\) of a turn or two out of eight equal parts of the circle. A \(\frac{3}{8}\) turn is equivalent to three out of eight equal parts of the circle.
(c) If \(\frac{1}{8}\) turn is half of a quarter turn then we shall make a right angle with \(\frac{2}{8}\) turn.
(d) If \(\frac{1}{8}\) turn is half of a quarter turn then we shall make a straight angle with \(\frac{4}{8}\) turn.
(e) A \(\frac{5}{8}\) turn is equivalent to five out of eight equal parts of the circle.
A \(\frac{6}{8}\) turn is equivalent to six out of eight equal parts of the circle. This is equivalent to \(\frac{3}{4}\) turn.
A \(\frac{7}{8}\) turn is equivalent to seven parts of the circle.
A \(\frac{8}{8}\) turn is equivalent to eight parts of the circle. This is equivalent to a full turn.
(f) Do yourself
Let Us Think (NCERT Pg 37)
Question 7.
(i) In the following circles, the end points of \(\frac{1}{2}\), \(\frac{1}{4}\) and \(\frac{1}{8}\) turns are shown. Draw arrows to show the starting points.
(ii) Cut out a circle from a tracing paper. First, fold the circle in half and then fold it again into 3 equal parts.
Attach a straw at the centre of the circle. Mark the starting point and show the turns equal to \(\frac{1}{6}\), \(\frac{2}{6}\) and so on until you complete a full circle.
Cut out \(\frac{1}{6}\) part and \(\frac{2}{6}\) part of the circle. Fold one of the \(\frac{1}{6}\) parts into half.
Can you guess what turn of the straw will be equal to half of a \(\frac{1}{6}\) turn? This is the same as a \(\frac{1}{12}\) turn.
Paste these parts on a thicker paper or board and you can use them as angle measuring tools.
Answer:
(i)
(ii) Do yourself.
Let Us Do (NCERT Pg 38-40)
Question 8.
Guess the measures of each of the angles shown below. Then, check using your angle measuring tools. You may need to use a combination of measures. Also, state whether each of the angles is acute, right or obtuse.
Answer:
(i) It is an acute angle.
(ii) It is an acute angle.
(iii) It is an acute angle.
(iv) It is an acute angle.
(v) It is a right angle.
(vi) It is an obtuse angle.
(vii) It is an obtuse angle.
Question 9.
Guess the measure of the turns made by the arrow in each of the following cases. Verify with a combination of angle measuring tools.
Answer:
We know that
Question 10.
Measure each arrgle in the given shapes. Write the measure of the angles in terms of turns and describe whether they are acute, obtuse or right angles.
Answer:
(i) Here, angle A measure in turns would be less than \(\frac{1}{4}\) turn then it forms an acute angle.
And angle B measure in turns would be also less than \(\frac{1}{4}\) turn then it forms an acute angle.
(ii) Angles D and D measure in turns would be less than \(\frac{1}{4}\) turn.
So, they form acute angle.
And angle E measure in turns would be between \(\frac{1}{4}\) and \(\frac{1}{2}\) turns. So, it forms an obtuse angle.
(iii) Angle F measure in turns would be less than \(\frac{1}{4}\) turn. So, it forms an acute angle. Angle F measure in turns would be \(\frac{1}{4}\) turn. So, it forms a right angle.
And angle G measure in turns would be between \(\frac{1}{4}\) and \(\frac{1}{2}\) turns. So, it forms an obtuse angle.
Question 11.
Draw angles for the given measures of turns using the given lines.
Answer:
Question 12.
Draw the angles formed by the following turns in your notebook.
\(\frac{1}{2}\) turn, \(\frac{1}{4}\) turn, \(\frac{2}{4}\) turn, \(\frac{1}{6}\) turn, \(\frac{4}{6}\) turn, \(\frac{3}{12}\) turn, \(\frac{1}{2}\) + \(\frac{1}{4}\) turn and \(\frac{1}{8}\) + \(\frac{1}{6}\) turn.
Answer:
Question 13.
Guess the measure of turns the minute hand of a clock makes in each of the following cases. The initial position of the minute hand is given.
Draw the final-position of the minute hand on the clock face. Discuss your reasoning in class.
(i) When the minute hand moves by 15 minutes, it has made a ………. turn of the circle.
(ii) When the minute hand moves by 30 minutes, it has made a ………. turn of the circle.
(iii) When the minute hand moves by 45 minutes, it has made a ………. turn of the circle.
(iv) When the minute hand has turned by \(\frac{1}{12}\) of a full turn, it has moved by ………. minutes.
(v) When the minute hand has turned a full-circle, it has moved by…….. minutes.
(vi) When the minute hand has turned by \(\frac{1}{6}\) of a full turn, it has moved by ………. minutes.
(vii) When the minute hand has turned by \(\frac{4}{12}\) of a full turn, it has moved by ………. minutes.
Answer:
(i) When the minute hand moves by 15 minutes, it has made a \(\frac{1}{4}\) turn of the circle.
(ii) When the minute hand moves by 30 minutes, it has made a \(\frac{1}{2}\) turn of the circle.
(iii) When the minute hand moves by 45 minutes, it has made a \(\frac{3}{4}\) turn of the circle.
(iv) Since, we know that a minute hand completes a full turn in 60 minutes.
So, when the minute hand has turned by \(\frac{1}{12}\) of a full turn, it has moved by \(\left(\frac{1}{12} \times 60\right)\) minutes that is 5 minutes.
(v) Since, we know that the minute hand completes a full turn in 60 minutes. So, when the minute hand has turned a full-circle, it has moved by 60 minutes.
(vi) Since, we know that the minute hand completes a full turn in 60 minutes. So, when the minute hand has turned by \(\frac{\mathbf{1}}{\mathbf{6}}\) × of a full turn, it has moved by \(\left(\frac{1}{6} \times 60\right)\) minutes i.e. 10 minutes.
(vii) Since, we know that the minute hand completes a full turn in 60 minutes. So, when the minute hand has turned by \(\frac{\mathbf{4}}{\mathbf{12}}\) of a full turn, it has moved by \(\left(\frac{4}{12} \times 60\right)\) minutes that is 20 minutes.
Which direction? (NCERT Pg 40)
Question 14.
The creatures below have made a quarter turn once. Tick the direction in which they have moved.
Answer:
(i) Clockwise
(ii) Clockwise
(iii) Anti-clockwise
(iv) Anti-clockwise
Try These (NCERT Pg 40)
Question 15.
Observe the direction of movement while opening a tap, unscrewing a lid or loosening a nut. Do they move clockwise or anti-clockwise?
Answer:
When opening a tap, unscrewing a lid or loosening a nut, the direction of movement is typically anti-clockwise.
Fun with Turns (NCERT Pg 40-41)
Question 16.
The children in a class are playing a game in which the teacher tells them the direction in which they should rotate. Complete the table by filling the direction the children will face on completing the given turns.
The starting direction is given in the table.
Answer:
The starting direction is given in the table.
Question 17.
Padma is facing the toy shop. What place will she face if she takes a half turn clockwise?
What other way can she turn to face the same place?
Answer:
- If Padma is facing the toy shop then a half turn clockwise will orient her face in the opposite direction, which is towards the Ice-cream stall.
- A half turn, regardless of whether it is clockwise or anti-clockwise, results in facing the starting direction.