Question

The lengths of the sides of a triangle are 10,14, , and 15 . What is the measure, of the angle opposite the longest side?

Answer 1

75.3°

Explanation:

Applies the Law of Cosines

15 represents the larger side and its opposite angle will be C

`15^(2) =10^(2) +14^(2) -2(10)(14)cosC`

`225=296-280cosC`

`-280cosC=225-296`

`cosC=(-71)/(-280)`

`C=ArcCos(0.25357)`

C = 75.3°

Hope this helps