# Question #7b017

Mar 25, 2017

Not valid.

#### Explanation:

The $\textcolor{b l u e}{\text{sum of the angles at a point}} = {360}^{\circ}$

To find z, sum the 4 given angles and subtract the result from 360.

$\Rightarrow \left(2 \times {108}^{2}\right) + \left(2 \times {72}^{\circ}\right) = 216 + 144 = {360}^{\circ}$

The 4 given angles make up the sum.