Correct Answer - Option 3 : 150˚ and 50˚
Given:
ABCD is a quadrilateral, ∠C = 90° and ∠D = 70°
Concept:
The sum of all angles in a quadrilateral is 360°.
Calculation:
Let assume that ∠B = x
So, ∠A = 3x
⇒ The sum of all angles in a quadrilateral is 360°.
⇒ ∠A + ∠B + ∠C + ∠D = 360°
⇒ 3x + x + 90° + 70° = 360°
⇒ 4x + 160˚ = 360°
⇒ 4x = 200°
⇒ x = 50°
∴ ∠B = x = 50°
And, ∠A = 3x = 50° × 3 =150°
The Correct option is 3 i.e. 150° and 50°
