Question

g the sums of the angle measures in quadrilaterals
rectangle abcd has four right angles.
√ 1. what is the sum of its angle measures? 360°√

1. move vertex a to a different location. which vertex angle remains

unchanged?

m∠a = 90°
m∠b = 90°
m∠c = 90°
m∠d = 90°

Explanation:

Step1: Analyze the properties of rectangle angles

In a rectangle, all angles are right angles (\(90^{\circ}\)). When vertex \(A\) is moved, the side \(BC\) remains parallel to \(AD\) (original property of rectangle). The angle at vertex \(C\) is formed by sides \(BC\) and \(CD\). Since \(BC\) and \(CD\) are not affected by moving vertex \(A\) (as \(BC\) is parallel to \(AD\) and \(CD\) is a fixed - length side in the original rectangle structure before moving \(A\)), the measure of \(\angle C\) remains \(90^{\circ}\).

Answer:

\(C\)