Question

The sum of the angel measures of a quadrilateral is 360. Find the value of x. The known numbers are 110, 90, and 80.

Answer 1

The sum of internal angles of a quadrilateral is always 360°.

So if the internal angles of a quadrilateral are 110, 90, 80 and x, we have that:

$\begin{gathered} 110+90+80+x=360 \\ 280+x=360 \\ x=360-280 \\ x=80\degree \end{gathered}$

So we have that x is equal 80°.