← Back to the activity

Grade 4 Math — Angles and the protractor

Name an angle as acute, right, obtuse or straight, and measure one with a protractor.

Name: ________________________

  1. 1.An angle measures 130°. What kind of angle is it?

    • a) Right
    • b) Straight
    • c) Acute
    • d) Obtuse

  2. 2.Three angles are drawn below. Tap the obtuse one.

    Write the number of the part.

    123

  3. 3.An angle is a third of a half turn. How many degrees is it?

  4. 4.Sort each angle by its name.

    Groups: Acute · Obtuse

    • 89°
    • 12°
    • 150°
    • 95°
    • 30°
    • 175°

  5. 5.Put these angles in order, smallest first.

    • 25°
    • 135°
    • 170°
    • 70°
    • 90°

  6. 6.Which of these could not be the size of an acute angle?

    • a) 60°
    • b) 89°
    • c) 91°
    • d) 15°

  7. 7.How many degrees are there in a half turn?

  8. 8.An angle is measured with a protractor. One arm reads 20 and the other reads 75. How many degrees is the angle?

Answer key — Grade 4 Math — Angles and the protractor

  1. 1. d) Obtuse
  2. 2. 3 — Angle C
  3. 3. 60
  4. 4. 30° → Acute; 95° → Obtuse; 89° → Acute; 150° → Obtuse; 12° → Acute; 175° → Obtuse
  5. 5. 1. 25° 2. 70° 3. 90° 4. 135° 5. 170°
  6. 6. c) 91°
  7. 7. 180
  8. 8. 55