Question

What is the measurement of BC to the nearest centimeter?

Answer 1

a 8

Explanation:

You are given two sides and the included angle. Since you don't have any side and the opposite angle, you must use the law of cosines.

`a^2 = b^2 + c^2 - 2bc\cos A`

`a^2 = 5^2 + 11^2 - 2(5)(11)\cos 39^\circ`

`a^2 = 25 + 121 - 110\cos 39^\circ`

`a^2 = 60.51`

`a = 7.779`

Answer: a = 8 cm