Question

Triangle Q R S is shown. The length of Q S is 17, the length of S R is 18, and the length of Q R is 10. Law of cosines: a2 = b2 + c2 – 2bccos(A) What is the measure of AngleS to the nearest whole degree? 19° 26° 30° 33°

Answer 1

Answer: the answer is 33

Explanation:

Answer 2

33 degrees

Explanation:

we know that

see the attached figure to better understand the problem

Applying the law of cosines

`QR^2=QS^2+SR^2-2(QS)(SR)cos(S)`

substitute the given values

`10^2=17^2+18^2-2(17)(18)cos(S)`

`100=289+324-(612)cos(S)`

`(612)cos (S)=613-100\\cos(S)=513/612\\S=cos^(-1)(513/612)\\S=33^o`