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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 Textbook Pages 32-33
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.
Solution:
In the second image, child A is facing backward or has made a half turn, child B is facings lightly sideways or has made an acute angle, child C has made a full turn as he is facing in the same direction, and child D has made a quarter turn. Thus, child C has made a full turn and child A has make a half turn.
Give examples of real-life situations where you observe turns.
Solution:
Real-life situations where you observe turns Taps, Door knobs, Turning your head to look back, Turning a key in a lock.
A giant wheel makes a full turn when it comes back to the starting position E.
Reema takes two half turns in the same direction.
It is like a ______turn
Solution:
It is like a full turn.
What happens if she takes 2 quarter turns in the same direction?
It is like a ______turn
Solution:
It is like a half turn.
What happens if she takes 4 quarter turns in the same direction?
It is like a ______turn
Solution:
It is like a full turn.
Write some of the everyday objects that involve turns. For example, taps, bottle caps, gas stove knobs, clock hands, fan regulators, and steering wheels.
What is the maximum possible turn in each of these cases? Check and tick.
Solution:
| Object | Less than 1 a \(\frac{1}{4}\) turn 4 | \(\frac{1}{4}\) turn 4 | More than a \(\frac{1}{4}\) turn 4 |
| Clothes clip | ✓ | ||
| Door with hinge | ✓ | ||
| Tongs | ✓ | ||
| Scissors | ✓ | ||
| File cover | ✓ |
Do any of the above objects make a half turn? Write their names below
Solution:
Yes, Door with hinge, and File cover make a half turn.
Do any of the above objects make a full turn? Write their names below
Solution:
None of these objects are designed to make a full turn.
NCERT Textbook Pages 34-36
Let Us Do
(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.
Use your paper fan to show different acute angles and obtuse angles.
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?
Solution:
Make a paper fan.
Make less than a \(\frac{1}{4}\) turn (acute angle).
Make less than a \(\frac{1}{4}\) turn (acute angle).
Put one above the other.
It is still less than \(\frac{1}{4}\) turn (acute angle).
So, two acute turns together can make another acute turn.
(b) You might have built houses using the hard covers 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: _____________
Solution:
A: Obtuse
B: Right
C: Acute
D: Acute
E: Acute
F: Right
G: Right
H: Obtuse
(c) Make a 5-sided shape with 2 right angles, 2 obtuse angles, and 1 acute angle in your notebook.
Solution:
(Answer may vary)
(d) Look at the angle formation between the legs of these gymnasts. Identify whether the angles are acute, obtuse, right or straight.
Solution:
NCERT Textbook Page 36
Angle Measuring Tool
Let us make point as shown:
(b) Now, try this.
Show a \(\frac{1}{8}\) turn of the straw.
Solution:
Show a \(\frac{2}{8}\) turn. Show a \(\frac{1}{4}\) turn. Show a \(\frac{3}{8}\) turn.
Solution:
Turn the straw by two \(\frac{1}{8}\)part of the circle clockwise or anticlockwise.
Since two \(\frac{1}{8}\) makes a \(\frac{1}{4}\), turn the straw by two parts of the circle clockwise or anti-clockwise.
Turn the straw by three parts of the circle clockwise or anti-clockwise.
What angle have you made with a \(\frac{2}{8}\) turn? A \(\frac{1}{8}\) turn is half of a quarter turn.
Solution:
Angle made with a \(\frac{2}{8}\) turn is a right angle.
Since, two \(\frac{1}{8}\) make a \(\frac{1}{4}\). So, a \(\frac{1}{8}\) turn is half of a quarter turn.
What angle have you made with a \(\frac{4}{8}\) turn?
Solution:
Turn the straw by four \(\frac{1}{8}\) parts of the circle clockwise or anticlockwise.
So, the angle made with a \(\frac{4}{8}\) turn is a straight angle.
NCERT Textbook Page 37
Let Us Think
Question 1.
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.
Solution:
\(\frac{1}{2}\) turn means the arrow points in the exact opposite direction from where it started. So, if the starting arrow pointed up, after a \(\frac{1}{2}\) turn, it points down.
Divide the circle into 8 equal parts. Now, turn the arrow by \(\frac{1}{8}\) to the left of the end point to get the starting point.
Divide the circle into 8 equal parts. Now turn the arrow by two \(\frac{1}{8}\) anti-clockwise to the left of the end points to get the starting point.
NCERT Textbook Pages 38-40
Let Us Do
Question 1.
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.
Solution:
Question 2.
Guess the measure of the turns made by the arrow in each of the following cases. Verify with a combination of angle measuring tools.
Solution:
Question 3.
Measure each angle in the given shapes. Writ.e the measure of the angles in terms of turns and describe whether they are acute, obtuse or right angles.
Solution:
(a) In the given figure, angles A are B’ show turn of less than \(\frac{1}{4}\), so they both are acute angles.
(b) In the given figure, angles D and D’ show a turn of less than \(\frac{1}{4}\). So, angles D and D’ are acute angles.
Angle E opens wider than \(\frac{1}{4}\) turn but less than a half turn, so angle E is an obtuse angle.
(c) In the given figure, only F shows a turn of less than \(\frac{1}{4}\), so angle F is an 4 acute angle and angle F’ shows a \(\frac{1}{4}\) turn, so angle F’ is a right F angle.
Angle G opens wider than \(\frac{1}{4}\) turn but less than a \(\frac{1}{2}\) turn, so angle G is an obtuse angle.
Question 4.
Draw angles for the given measures of turns using the given lines.
Solution:
Question 5.
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
Solution:
Question 6.
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.
(a) When the minute hand moves by 15 minutes, it has made a _______ turn of the circle.
Solution:
When the minute hand moves by 15 minutes, it has made a \(\frac{1}{4}\) turn of the circle.
(b) When the minute hand moves by 30 minutes, it has made a _______ turn of the circle.
Solution:
When the minute hand moves by 30 minutes, it has made a \(\frac{1}{2}\) turn of the circle.
(d) When the minute hand has turned by \(\frac{1}{12}\) of a full turn, it has moved by ______ minutes.
Solution:
When the minute hand has turned by \(\frac{1}{12}\) of a full turn, it has moved by ______ minutes.
(e) When the minute hand has turned a full-circle, it has moved by ______ minutes.
Solution:
When the minute hand has turned a full-circle, it has moved by \(\frac{3}{4}\) minutes.
(f) When the minute hand has turned by \(\frac{1}{6}\) of a full turn, it has moved by _____ minutes.
Solution:
When the minute hand has turned by \(\frac{1}{6}\) of a full turn, it has moved by 60 minutes.
(g) When the minute hand has turned by \(\frac{4}{12}\) of a full turn, it has moved by _____ minutes.
Solution:
When the minute hand has turned by \(\frac{4}{12}\) of a full turn, it has moved by 20 minutes.
NCERT Textbook Page 40
Which direction?
The creatures below have made a quarter turn once. Tick the direction in which they have moved
Try these
Observe the direction of movement while opening a tap, unscrewing a lid or loosening a nut. Do they move clockwise or anti-clockwise?
Solution:
Direction of movement while:
Opening a tab → Anti-clockwise
Unscrewing a lid or loosening a nut → Anti¬clockwise
NCERT Textbook Pages 40-41
Fun with Turns
Question 1.
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.
Solution:
Question 2.
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?
Solution:
Since, Padma is facing toy shop, a half turn clockwise means Padma will face the opposite direction. So, she will now face the Ice Cream cart.
She can also take a half turn anti-clockwise to face the same place i.e., Ice Cream cart.