Math 7 · Unit 5: Angles and constructions · Cambridge Lower Secondary Maths Stage 7

Questions

1. 1. Worked example: three of the angles of a quadrilateral are 55°, 108° and 123°. Calculate the fourth angle.

   • 286°
   • 106°
   • 74°
   • 84°
   Check

2. 2. Question 1a: AB is a straight line. A line meets it, making an angle of 137° on one side and a on the other. Calculate a.

   • 223°
   • 137°
   • 53°
   • 43°
   Check

3. 3. Question 1b: CD is a straight line. Two lines meet it at the same point, making three angles on one side: 31°, b and 38°. Calculate b.

   • 69°
   • 291°
   • 111°
   • 101°
   Check

4. 4. Question 2a: two lines meet at a point. The angle on one side is 165°. What is the angle a all the way round on the other side?

   • 15°
   • 195°
   • 165°
   • 185°
   Check

5. 5. Question 2b: three angles around a point are 94°, 119° and b. Work out b.

   • 157°
   • 33°
   • 147°
   • 213°
   Check

6. 6. Question 2c: four angles around a point are 85°, 65°, 95° and c. Work out c.

   • 245°
   • 125°
   • 35°
   • 115°
   Check

7. 7. Question 3a: a quadrilateral has angles a, 110°, 80° and 110°. Calculate a.

   • 70°
   • 60°
   • 300°
   • 160°
   Check

8. 8. Question 3b: a quadrilateral has angles 75°, 105°, 75° and b. Calculate b.

   • 115°
   • 255°
   • 75°
   • 105°
   Check

9. 9. Question 4a: in diagram a, the angles on the line XY are 63° and 117°. Which statement is true?

   • 63° + 117° = 360°, angles around a point.
   • 63° + 117° = 180°, angles on a straight line.
   • 117° is an obtuse angle, so XY is not a straight line.
   • 63° + 117° = 190°, so XY is not a straight line.
   Check

10. 10. Question 4b: in diagram b, the angles on the line XY are 132° and 48°. Which statement is true?

    • 132° + 48° = 190°, so XY is not a straight line.
    • 132° + 48° = 180°, angles on a straight line.
    • 132° + 48° = 360°, angles around a point.
    • 48° is an obtuse angle, so XY is not a straight line.
    Check

11. 11. Question 4: give a reason why diagram c is the odd one out.

    • Diagram c has the smallest angle.
    • 124° is an obtuse angle.
    • 54° + 124° = 180°, like the others.
    • 54° + 124° = 178°, not 180°, so XY in c is not a straight line.
    Check

12. 12. Question 5: one angle of a quadrilateral is 135°. All the other angles are the same size. Work out the size of the other angles.

    • 75°
    • 225°
    • 112.5°
    • 45°
    Check

13. 13. Question 6a: calculate the value of a.

    • 80°
    • 100°
    • 65°
    • 90°
    Check

14. 14. Question 6b: calculate the value of b.

    • 70°
    • 110°
    • 65°
    • 105°
    Check

15. 15. Question 7: one angle of a parallelogram is 62°. Work out the size of the other three angles.

    • 62°, 62° and 62°
    • 118°, 118° and 118°
    • 62°, 98° and 138°
    • 62°, 118° and 118°
    Check

16. 16. Question 8: calculate the value of x.

    • x = 10°
    • x = 350°
    • x = 0°
    • It cannot be done: 95° + 125° + 150° = 370°, which is more than 360°, so the diagram is impossible.
    Check

17. 17. Question 9: this diagram is made from a square and two equilateral triangles. Calculate the value of y.

    • 120°
    • 90°
    • 150°
    • 210°
    Check

18. 18. Question 10a: two quadrilaterals have eight angles in total. Could the angles be 50°, 60°, 70°, 80°, 90°, 100°, 110° and 120°?

    • Yes
    • No
    Check

19. 19. Question 10b: two quadrilaterals have eight angles in total. Could the angles be 20°, 40°, 60°, 80°, 100°, 120°, 140° and 160°?

    • Yes
    • No
    Check

20. 20. Question 11: a kite is a quadrilateral with a line of symmetry. One angle of a kite is 120°. Another angle is 90°. Which of these could NOT be the other two angles?

    • 90° and 60°
    • 100° and 50°
    • 120° and 30°
    • 75° and 75°
    Check