Question

Help me please! Thanks!

Answer 1

The measure of x is 88°.

Solution:

p = 16, q = 12 and r = 11

To find the angle of P:

Using cosine formula:

$p^{2}=q^{2}+r^{2}-2qr \cos P$

$16^{2}=12^{2}+11^{2}-2\times12 \times11 \cos x^\circ$

$256=144+121-264 \cos x^\circ$

$256=265-264 \cos x^\circ$

Subtract 265 from both sides.

$-9=-264 \cos x^\circ$

Divide by -264 on both sides.

$\frac{-9}{-264} =\frac{ -264 \cos x^\circ}{-264}$

$\frac{3}{88} =\cos x^\circ$

$\cos^{-1} \frac{3}{88} =x^\circ$

88.05° = x°

88° = x°

The measure of x is 88°.