Practice identifying acute angles, comparing them to right angles, and explaining why acute angles measure less than 90 degrees.
Read each problem carefully. Decide whether the angle is acute, and explain your thinking when asked. Show your work in the space provided.
Identify and describe angles smaller than a right angle
Geometry - Grade 4-5
- 1
An angle measures 35 degrees. Is it acute? Explain how you know.
- 2
Look at an angle that is smaller than the corner of a square. Is the angle acute, right, or obtuse?
- 3
Circle the angle measurement that is acute: 90 degrees, 120 degrees, 45 degrees, or 180 degrees.
- 4
Angle B measures 89 degrees. Is angle B acute? Explain your answer.
- 5
A student says an angle that measures 90 degrees is acute. Is the student correct? Explain.
- 6
Use the diagram to decide which labeled angles are acute: angle A, angle B, and angle C.
- 7
Order these angle measures from smallest to largest: 75 degrees, 15 degrees, 60 degrees, 89 degrees.
- 8
Draw an acute angle and label it with a possible degree measure.
- 9
A pair of scissors is opened slightly. The angle between the blades is about 25 degrees. Is the angle acute, right, or obtuse?
- 10
Write three different angle measures that are acute.
- 11
Angle D is shown smaller than a right angle. If the choices are 30 degrees, 90 degrees, and 130 degrees, which measure could be angle D?
- 12
Complete the sentence: An acute angle is an angle that measures blank 90 degrees.