### Instruction: In parallelogram $ABCD$, the measure of angle $ABC$ is 3 times the measure of angle $BCD$. How many degrees are in the measure of angle $ADC$?### Response: I know that opposite angles in a parallelogram are equal, so angle $ABC$ is also equal to angle $CDA$.
Let me call the measure of angle $BCD$ x degrees, then angle $ABC$ is 3x degrees.
Since the sum of the angles in a parallelogram is 360 degrees, I can write an equation: $3x + x + 3x + x = 360$.
Simplifying, I get $8x = 360$, so $x = 45$.
Therefore, angle $ADC$ is 3x degrees, which is 3 times 45, which is 135 degrees.