Question

Four students explain how to find the measure of ZRST in this diagram.

S
75°
53 R
т
Which student correctly explains how to find the measure of ZRST given the angle measures shown?
A Amy says to use vertical angles to find the measure of ZSRT and add this measure to 75º.
® Brett says to use complementary angles to find the measure of ZSRT and add this measure to 75º.
© Cate says to use vertical angles to find the measure of ZSRT, add this measure to 75º. and then subtract
from 180
D Dylan says to use complementary angles to find the measure of ZSRT, add this measure to 75°, and then
subtract the sum from 180°

Answer 1

To find the angle RST we have to first find SRT As the exterior angle adjoined with SRT =53°

so the SRT = Outer angle adjoined with angle SRT

angle SRT = 53° [°.° vertically opposite angles are equal]

Angle SRT + Angle STR + Angle RST = 180°

=>53° + 75° + Angle RST =180°

=> 128° + Angle RST = 180°

=> Angle RST =(180-128)°

= 52°

SO NO. C IS correct what Cate says is absolutely right