Page 299 - ICSE Math 7

30. One-sixth of the supplement of an angle is 20° less than its complement. Find the angle.

z

31. For the adjoining figure, find angles x, y and z. 135°
y
x x
A

48°
32. In the adjoining figure, BD is the bisector of ∠ABC and CD is the
bisector of ∠ACB, find ∠BDC.
D
X
B C

33. In the adjoining figure, XY = PY and YZ = YQ.
Prove that ∆XYZ ≅ ∆PYQ. Q
A
Y Z P

34. In the adjoining figure, AB = AC and D and E are two points on AB D E
and AC respectively such that AD = AE. Prove that DC = EB.

B C
35. Plot the reflection of the following points in origin on a graph paper.

(a) A(–5, 3) (b) B(3, 2) (c) C(1, –2)
36. Which of the following has rotational symmetry about the point O? Also, write the order of the
rotational symmetry.
(a) (b)

O
O

37. What is the relation between the faces, edges and vertices of a polyhedron? A polyhedron has
12 vertices, 20 faces and n edges. Find n.

38. Guess the number of cubes in the given arrangement.

39. Draw ∠ABC = 80°. Take a point P on AB such that PB = 4 cm. Draw a line parallel to BC
passing through P.

40. Construct an isosceles triangle when one of its equal sides is 7.2 cm and the vertical angle is
50°.

285