Angles questions for Primary 5 Maths

Every answer with the reasoning behind it. Worth reading after you have tried the set — or on its own, if you are a parent marking it.

1. Three angles sit on a straight line. Two of them are 47° and 63°. What is the third?

   Answer: 70°

   47 + 63 = 110, and 180 − 110 = 70°.

2. Four angles meet at a point. Three of them are 90°, 120° and 75°. What is the fourth?

   Answer: 75°

   90 + 120 + 75 = 285, and 360 − 285 = 75°.

3. Two straight lines cross. One of the angles formed is 118°. What is the angle vertically opposite it?

   Answer: 118°

   Vertically opposite angles are always equal, so it is also 118°.

4. Two straight lines cross. One of the angles is 74°. What is the angle next to it?

   Answer: 106°

   Angles next to each other on a straight line add to 180°: 180 − 74 = 106°.

5. A triangle has angles of 40° and 95°. What is its third angle?

   Answer: 45°

   180 − 40 − 95 = 45°.

6. What kind of angle measures 200°?

   Answer: Reflex

   An angle greater than 180° and less than 360° is reflex.

7. Two equal angles and a right angle meet at a point. What is the size of each equal angle?

   Answer: 135°

   360 − 90 = 270° shared between two equal angles, so each is 135°.

8. An angle on a straight line is three times the angle next to it. What is the larger angle?

   Answer: 135°

   The two angles are 1 unit and 3 units, so 4 units = 180°, 1 unit = 45°, and 3 units = 135°.

9. In a quadrilateral, three angles are equal and the fourth is 120°. What is each of the equal angles?

   Answer: 80°

   360 − 120 = 240° shared between three equal angles, so each is 80°.

10. Through how many degrees does the minute hand of a clock turn between 2.15 p.m. and 2.45 p.m.?

    Answer: 180°

    30 minutes is half an hour, and half of 360° is 180°.