Exercise 4 Page 37

We have been asked to find the measure of angle $R P T .$ The expression $m ∠ R P T$ tells us to find the measure of the angle between rays $P R$ and $P T .$ Similarly, $m ∠ R P B$ tells us to find the angle between rays $P R$ and $P B .$ Let's start by identifying the three angles.

It is given that

P B

is the angle bisector which means that it divides

∠ R P T

into two congruent angles,

∠ R P B

and

∠ B P T .

Therefore the measures of

∠ R P B

and

∠ B P T

are equal.