Solution:
The given statement is :Two supplementary angles are congruent.
Two angles are said to be supplementary if sum of these two angles is 180°.
Let one Angle be A, then another angle will be 180 - A.
As given:
A≅180-A
A=180 -A
A +A= 180
2 A = 180
Dividing both sides by 2, we get
A= 90°
The Measure of each angle will be of 90°.
i.e , d = 90°
