Question

A scalene triangle has the lengths 6, 11, and 12. keyla uses the law of cosines to find the measure of the largest angle. complete her work and find the measure of angle y to the nearest degree. 1. 122 = 112 62 − 2(11)(6)cos(y) 2. 144 = 121 36 − (132)cos(y) 3. 144 = 157 − (132)cos(y) 4. −13 = −(132)cos(y)

Answer 1

the answer is just 84 i already did it 

Answer 2

Sometimes the editor can make life a little frustrating. There are parts I can't read easily, but here's how you do the problem.

The largest angle is going to be opposite the longest line.

c^2 = b^2 + a^2 - 2 *a * b * Cos C
c = 12
b = 11
a = 6
C = ???

12^2 = 11^2 + 6^2 - 2*11*6 * Cos C
144 = 121 + 36 - 132 * Cos C
144 = 157 - 132 * Cos C
144 - 157 = -132 * Cos C
-13 = -132 Cos C
-13/-132 = Cos C
0.09848 = Cos C
Cos-1(0.09848) = C
84.348 degrees