Question

100 POINTS

Quadrilateral ABCD has the following angle measures:

m∠A = 112°, m∠B = 130°, m∠C = ?°, m∠D = 90°

What is m∠C?

Answer 1

• m∠C = 28°

Explanation:

Interior angles of the quadrilateral sum to 360°:

• m∠A + m∠B + m∠C + m∠D = 360
• 112 + 130 + m∠C + 90 = 360
• m∠C + 332 = 360
• m∠C = 360 - 332
• m∠C = 28

Answer 2

m∠C = 28°

Explanation:

The interior angles of a quadrilateral sum to 360°.

Given:

• m∠A = 112°
• m∠B = 130°
• m∠D = 90°

Therefore:

⇒ m∠A + m∠B + m∠C + m∠D = 360°

⇒ 112°+ 130° + m∠C + 90° = 360°

⇒ 332° + m∠C = 360°

⇒ m∠C = 360° - 332°

⇒ m∠C = 28°