Question

classify the four angles of the quadrilateral.
a 110° 90°
b 60°
c 100°
right acute obtuse
∠a ○ ○ ○
∠b ○ ○ ○
∠c ○ ○ ○
∠d ○ ○ ○

Explanation:

Step1: Recall angle - type definitions

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

Step2: Classify ∠A

Since ∠A = 110°, and 90° < 110° < 180°, ∠A is obtuse.

Step3: Classify ∠B

Since ∠B = 60°, and 60° < 90°, ∠B is acute.

Step4: Classify ∠C

Since ∠C = 100°, and 90° < 100° < 180°, ∠C is obtuse.

Step5: Classify ∠D

Since ∠D = 90°, ∠D is right.

Answer:

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