Page 33
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 full turn.
What happens if she takes 2 quarter turns in the same direction? It is like a half turn.
What happens if she takes 4 quarter turns in the same direction? It is like a full turn.
Write some of the everyday objects that involve turns. For example, taps, door knobs, screwdrivers, wheels, keys, and jar lids.
What is the maximum possible turn in each of these cases? Check and tick.
Let Us Do (Page 35)
Question (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.
Answer: A: Obtuse angle B: Right angle C: Acute angle D: Acute angle E: Acute angle F: Right angle G: Right angle H: Obtuse angle
Question (c): Make a 5-sided shape with 2 right angles, 2 obtuse angles, and 1 acute angle in your notebook.
Answer:
Look at the angle formation between the legs of these gymnasts. Identify whether the angles are acute, obtuse, right or straight.
Answer:
Let Us Think
In the following circles, the end points of turns are shown. Draw arrows to show the starting points.
Answer:
Let Us Do (Page 38)
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.
Answer:
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.
Answer:
Let Us Do (Page 39)
4: Draw angles for the given measures of turns using the given lines.
Answer:
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.
(b) When the minute hand moves by 30 minutes, it has made a _______ turn of the circle.
(c) When the minute hand moves by 45 minutes, it has made a _______ turn of the circle.
(d) When the minute hand has turned by 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.
Answer:
Let Us Do (Page 40)
(f) When the minute hand has turned by 1/6 of a full turn, it has moved by _____ minutes.
(g) When the minute hand has turned by 4/12 of a full turn, it has moved by _____ minutes.
Answer:
Which direction? (Page 40)
The creatures below have made a quarter turn once. Tick the direction in which they have moved.
Answer:
Try these (Page 40)
Question: Observe the direction of movement while opening a tap, unscrewing a lid or loosening a nut. Do they move clockwise or anti-clockwise?
Answer:
• Opening a tap: Usually anti-clockwise (lefty loosey, righty tighty).
• Unscrewing a lid: Anti-clockwise.
• Loosening a nut: Anti-clockwise.
Fun with Turns (Page 9)
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.
Answer:
2. Padma is facing the toy shop. What place will she face if she takes a half turn clockwise?
Answer: She will face the ice cream side
What other way can she turn to face the same place?
Answer: She can turn a half turn anti clockwise to face the same side.
usually not a full turn without special hinges or breaking.)