Question

What is the measurement of BC to the nearest centimeter?

Answer 1

Answer:

a   8

Step-by-step 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