In Fig. 5.38, l ||m||n.

∠QPS = 35° and ∠QRT = 55°. Find ∠PQR.

The drawings below (Fig. 5.37), show angles formed by the goalposts at different positions of a football player. The greater the angle, the better chance the player has of scoring a goal. For example, the player has a better chance of scoring a goal from Position A than from Position B.

In Parts (a) and (b) given below it may help to trace the diagrams and draw and measure angles.

a) Seven football players are practicing their kicks. They are lined up in a straight line in front of the goalpost [Fig.(ii)]. Which player has the best (the greatest) kicking angle?

b) Now the players are lined up as shown in Fig. (iii). Which player has the best kicking angle?

c) Estimate at least two situations such that the angles formed by different positions of two players are complement to each other.

The sum of two vertically opposite angles is 166°. Find each of the angles.

In Fig. 5.39, P, Q and R are collinear points and TQ ⊥ PR,

Name; (a) pair of complementary angles

(b) two pairs of supplementary angles.

(c) four pairs of adjacent angles.

In Fig. 5.40, OR ⊥ OP.

(i) Name all the pairs of adjacent angles.

(ii) Name all the pairs of complementary angles.