Question

classify the four angles of the quadrilateral.
c
60°
b
140°
a
70°
90°
d
right acute obtuse
∠a o o o
∠b o o o
∠c o o o
∠d o o o

Explanation:

Step1: Recall angle - type definitions

An acute angle is between 0° and 90°, a right - angle is 90°, and an obtuse angle is between 90° and 180°.

Step2: Classify ∠A

Since ∠A = 70° and 0°<70°<90°, ∠A is acute.

Step3: Classify ∠B

Since ∠B = 140° and 90°<140°<180°, ∠B is obtuse.

Step4: Classify ∠C

Since ∠C = 60° and 0°<60°<90°, ∠C is acute.

Step5: Classify ∠D

Since ∠D = 90°, ∠D is right.

Answer:

	Right	Acute	Obtuse
∠B			●
∠C		●
∠D	●