Answer
$a=60$
Work Step by Step
The sum of the four angles inside a quadrilateral is $360^\circ$.
Thus, the equation needed to find the value of $a$ is:
$$2a^\circ+2a^\circ+a^\circ+a^\circ=360^\circ$$
Solve the equation:
$$\begin{align*}
6a^\circ&=360^\circ &\text{Combine like terms.}\\
\frac{6a^\circ}{6}&=\frac{360^\circ}{6} &\text{Divide 6 to both sides.}\\
a^\circ&=60^\circ &\text{Simplify.}\\
a&=60
\end{align*}$$
Using a protractor to measure the angle confirms the measurement is reasonable.
Thus, $a=60$.
