Question

In ΔSTU, s = 6.1 cm, t = 3.2 cm and u=7.4 cm. Find the measure of ∠S to the nearest 10th of a degree.

Answer 1

54.1°

Explanation:

Answer 2

m∠S = 54.1°

Explanation:

Use the law of cosines

`s^(2) = t^(2) + u^(2) - 2utcos S\\6.1^(2) = 3.2^(2) + 7.4^(2) - 2(3.2)(7.4) cos S`

37.21 = 10.24 + 54.76 - 47.36 cos S

-27.79 = -47.36 cos S

.586782 = cos S

arccos .586782 = S

m∠S = 54.1°