Identifying Angles in a Figure

1. Ali bends a straw as below. Mark the angle formed by it.

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An angle is the amount of turning between two lines meeting at a point.
The bent straw (presented by the blue lines) forms an angle as marked by the red turning.

2. Following are examples of angles on objects we see everyday.

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On each object, the angles are marked by the yellow turning.

3. Here are some pairs of pencils placed in pairs.
Which of these pairs form angles?

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Pairs A, C and D form angles.
When 2 lines meet at a point, they form an angle at that point.

4. Study the angles below.

    a. Which angle is the smallest?

    b. Which angle is the greatest?

    c. Arrange the angles in order, beginning with the smallest.

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a. The lines forming Angle Y have the smallest turning.
     So, ∠Y is the smallest angle.
We denote angle using the symbol ∠.
b. The lines forming Angle X have the greatest turning.
     So, ∠X is the greatest angle.
c. Beginning with the smallest, the angles can be arranged as below:
         ∠Y,     ∠Z,     ∠X

5. Rayan makes some shapes as shown below.
How many sides and angles does each shape have?

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Shape A has 3 sides and 3 angles.
Shape B has 4 sides and 4 angles.
Shape C has 5 sides and 5 angles.
Shape D has 6 sides and 6 angles.