Let x be the common angle of quadrilateral.
As per question,
\(\angle\)A = 85°
\(\angle\)B = 75°
\(\angle\)C = \(\angle\)D = x
As we know that, Sum of all four angles of quadrilateral is 360o
\(\angle\)A + \(\angle\)B + \(\angle\)C + \(\angle\)D = 360°
85° + 75°+ x + x = 360°
2x = 360° - (85° + 75°)
2x = 200°
X = 200 / 2
= 100°
\(\angle\)C = \(\angle\)D = 100°
So, Two angles of quadrilateral whose measuring’s are equal is 100°.