Page 174 - ICSE Math 7

l
m
2. In the adjoining figure, l || m and n is a transversal. If ∠1= 65°, 2 6
find all the other angles. 1 5
3 4 7 8 n

3. In which of the following figures is AB || CD?

C A C A
A C
(a) 61° F (b) 100° 80° (c) 75°
E 60° 105°
D B B
B D D

4. If PQ || RS for the following figures, find the value of x.

P
R P Q

(a) 2x + 45° (b) 130° 100°
3x + 35°
Q R x S
S

5. Divide 140° into two adjacent angles such that the larger angle is 20° more than the smaller angle.
6. Two angles are in the ratio 1 : 6. If each angle is increased by 20°, they become supplementary
angles. Find the angles.
7. Find the angle which is equal to half of its supplement.
8. In the following figures, PQ || RS. Find x, y and z.

P R T
P x Q x P z
z z 45° Q
(a) 115° 110° (b) y (c) y x
R y S 55°
Q S R 56° 64°
S

THINK SMART

1. How many straight angles does the minute hand of a clock between 3 a.m. and 3 p.m. make?

2. Find the magnitude of the reflex angle of ∠AOB = 25° 46' 18''.
3. Fill in the blanks with the correct measure.
(a) If ∠A and ∠B are complementary angles, then ∠A + ∠B = ____________.

(b) If ∠A represents a reflex angle, then the possible measure of ∠A is ____________.
(c) If ∠P represents an angle that is congruent to an angle measuring 125°, then
∠P = ____________.
(d) If ∠P and ∠Q form a linear pair, then ∠P = ____________.

160