Question

HELP!! What is the approximate measure of angle x in the triangle shown?

60.3 degrees
80.4 degrees
117.1 degrees
130.5 degrees

Answer 1

Answer: D) 130.5 degrees

=================================================

Work Shown:

`c^2 = a^2 + b^2 - 2*a*b*\cos(C)\\\\10^2 = 5^2 + 6^2 - 2*5*6*\cos(x)\\\\100 = 25 + 36 - 60*\cos(x)\\\\100 = 61 - 60*\cos(x)\\\\100 - 61 = - 60*\cos(x)\\\\39 = - 60*\cos(x)\\\\\cos(x) = (39)/(-60)\\\\\cos(x) = -0.65\\\\x = \arccos(-0.65)\\\\x \approx 130.5416\\\\x \approx 130.5\\\\`

Note: I used the law of cosines. Make sure your calculator is in degree mode.