Answer:
∠ T ≈ 54.7°
Step-by-step explanation:
Using the cosine ratio in the right triangle
cos T = [tex]\frac{adjacent}{hypotenuse}[/tex] = [tex]\frac{ST}{TU}[/tex] = [tex]\frac{\sqrt{21} }{3\sqrt{7} }[/tex] = [tex]\frac{\sqrt{3} }{3}[/tex] , then
∠ T = [tex]cos^{-1}[/tex] ([tex]\frac{\sqrt{3} }{3}[/tex] ) ≈ 54.7° ( to 1 dec. place )
