Chapter 16 – Quadrilaterals
Practice set 37
Observe the figures below and find out their names.
1.
Ans: Pentagon (5 sides)
2.
Ans: Hexagon (6 sides)
3.
Ans: Heptagon (7 sides)
4.
Ans: Octagon (8 sides)
Practice set 38
1. Draw XYZW and name the following.
(1) The pairs of opposite angles.
Ans: ∠X and ∠Z, ∠W and ∠Y
(2) The pairs of opposite sides.
Ans: Seg XW and Seg WZ, Seg WZ and Seg ZY, Seg ZY and Seg XY, Seg XY and Seg XW
(3) The pairs of adjacent sides.
Ans: Seg XW and Seg YZ, Seg WZ and Seg XY.
(4) The pairs of adjacent angles.
Ans: ∠X and ∠W, ∠W and ∠Z, ∠Z and ∠Y, Y and ∠X.
(5) The diagonals of the quadrilateral.
Ans: Seg XZ and Seg WY.
(6) The name of the quadrilateral in different ways.
Ans: □XWZY, □WZYX, □ZYXW, □YXWZ.
2. In the table below, write the number of sides the polygon has.
Ans:
3. Look for examples of polygons in your surroundings. Draw them.
Ans: Students should do this on their own.
4. We see polygons when we join the tips of the petals of various flowers. Draw these polygons and write down the number of sides of each polygon.
Ans: Students should do this on their own.
5. Draw any polygon and divide it into triangular parts as shown here. Thus work out the sum of the measures of the angles of the polygon.
Ans:
Given polygon is a Pentagon which is made up of 3 triangles.
Sum of all the angles of a triangle = 180⁰
∴ Sum of all the angles of 3 triangles
= 3 × 180⁰
= 540⁰
Ans: Sum of all the angles of a Pentagon is 540⁰.