Question

find the sine of angle R

there are two similar right triangles, one has unknown lengths and angles which are classified as T, R, S, the other triangle has Line WV which has a length of 4, Line WU which has a length of 5, and Line UV which has a length of 3

Angle S corresponds with V

Answer 1

WV = 4, WU = 5, UV = 3 is a 3-4-5 right triangle with hypotenuse WU = 5 and right angle at V. If S corresponds to V, then R corresponds to U. So

sin(R) = sin(U) = (side opposite U)/(hypotenuse) = WV/WU = 4/5.