Question

classify the four angles of the quadrilateral.
right acute obtuse
∠a
∠b
∠c
∠d
90°
90°
75°
105°

Explanation:

Step1: Recall angle - type definitions

An acute angle is less than 90°, a right angle is equal to 90°, and an obtuse angle is greater than 90° and less than 180°.

Step2: Classify ∠A

Since ∠A = 90°, it is a right - angle.

Step3: Classify ∠B

Since ∠B=75°<90°, it is an acute angle.

Step4: Classify ∠C

Since ∠C = 105°>90° and ∠C<180°, it is an obtuse angle.

Step5: Classify ∠D

Since ∠D = 90°, it is a right - angle.

Answer:

∠A: Right
∠B: Acute
∠C: Obtuse
∠D: Right