Answer:
∠ R ≈ 39°
Step-by-step explanation:
Using the cosine ratio in the right triangle
cos R = [tex]\frac{adjacent}{hypotenuse}[/tex] = [tex]\frac{RS}{QR}[/tex] = [tex]\frac{61}{78}[/tex] , then
∠ R = [tex]cos^{-1}[/tex] ([tex]\frac{61}{78}[/tex] ) ≈ 39° ( to the nearest degree )
