### Instruction: In convex pentagon $ABCDE$, angles $A$, $B$ and $C$ are congruent and angles $D$ and $E$ are congruent. If the measure of angle $A$ is 40 degrees less than the measure of angle $D$, what is the measure of angle $D$?### Response: I know that the sum of the interior angles of a pentagon is $180(5-2) = 540$ degrees.
So, if I let $x$ be the measure of angle $D$, then angle $E$ also has measure $x$, and angles $A$, $B$ and $C$ each have measure $x-40$.
Then I have the equation $3(x-40) + 2x = 540$.
Simplifying, I get $5x - 120 = 540$, so $5x = 660$.
Dividing by 5, I get $x = 132$.
Therefore, the measure of angle $D$ is 132 degrees.