Answer:
The measure of ∠ADC is 150°
Explanation:
A parallelogram is a quadrilateral having parallel sides
The basic principle in solving this problem is knowing that opposite angles are congruent meaning they are equal.
Please check attachment for diagrammatic representation.
Now, we have represented ∠BCD by x°, what this means is that ∠ABC will be 5x°. Also, using the opposite angles are congruent property we raised earlier, ∠CAB will be x° while ∠ADC will be 5x°
To get the value of x, the parallelogram property we will be using is that the sum of the interior angles in a parallelogram is 360°.
Therefore, adding all these angles together, we have;
x + x + 5x + 5x + 360
12x = 360
x = 360/12
x = 30°
The measure of ∠ADC is 5x which is 5 × 30 = 150°