Answer:
see explanation
Explanation:
Since the figures are similar then the ratios of corresponding sides are equal, that is
=
( cross- multiply )
9x = 72 ⇒ x = 8
Also
=
( cross- multiply )
6a = 45 ⇒ a = 7.5
And
=
( cross- multiply )
6b = 63 ⇒ b = 10.5
Corresponding angles in the 2 figures are congruent, thus
∠s = 83°
Each lower base angle is supplementary to the upper base angle on the same side, hence
∠r = 180° - 30° = 150°