Question

What is the measure of Angle R

Answer 1

D, 25.21°

Explanation:

Law of cosines:

`r^2=c^2+t^2-2ct\ cos\angle R`

to which, replacing values we get

`9=36+49-2(6)(7) cos \angle R\\cos \angle R = \frac {76}{84}\approx 0.90}\\\angle R \approx 25.2087...`