Math 9 · Unit 5: Angles · Cambridge Lower Secondary Maths Stage 9

Questions

1. 1. The diagram shows two parallel lines crossed by two other lines. Work out the values of a, b, c and d.

   • a = 100, b = 100, c = 55, d = 125
   • a = 80, b = 80, c = 125, d = 55
   • a = 80, b = 80, c = 55, d = 125
   • a = 80, b = 80, c = 45, d = 135
   Check

2. 2. Which of these could be the angles of a quadrilateral? Tick the 2 sets.

   Tick all the right answers.

   • ☐ A: 70°, 80°, 90°, 100°
   • ☐ B: 60°, 80°, 90°, 130°
   • ☐ C: 50°, 80°, 105°, 125°
   Check

3. 3. In the diagram, B and C lie on a straight line. Is triangle ABC isosceles?

   • Yes
   • No
   Check

4. 4. The diagram shows two parallel vertical lines and two sloping lines that meet. Work out the values of a, b and c.

   • a = 100, b = 75, c = 25
   • a = 100, b = 105, c = 25
   • a = 100, b = 105, c = 155
   • a = 80, b = 75, c = 25
   Check

5. 5. The diagram shows two pairs of parallel lines and a line joining two crossing points. Work out the values of a, b and c.

   • a = 49, b = 49, c = 97
   • a = 49, b = 83, c = 48
   • a = 49, b = 49, c = 48
   • a = 131, b = 49, c = 48
   Check

6. 6. This shape has two equal angles x°. The angle marked 110° is outside the shape. Work out the value of x.

   • 10
   • 100
   • 40
   • 30
   Check

7. 7. Two angles of a triangle are 45° and 60°. What is the third angle?

   • 75°
   • 105°
   • 85°
   • 255°
   Check

8. 8. Two angles of a triangle are 45° and 60°. What are the sizes of its three exterior angles?

   • 135°, 120° and 105°
   • 135°, 120° and 75°
   • 45°, 60° and 75°
   • 90°, 60° and 30°
   Check

9. 9. In the diagram, a line crosses a triangle. Work out the values of x, y and z.

   • x = 95, y = 39, z = 124
   • x = 95, y = 49, z = 124
   • x = 95, y = 39, z = 56
   • x = 85, y = 39, z = 124
   Check

10. 10. In the diagram, four straight lines cross. Work out the values of x, y and z.

    • x = 40, y = 30, z = 80
    • x = 50, y = 40, z = 80
    • x = 50, y = 30, z = 80
    • x = 50, y = 30, z = 100
    Check

11. 11. The diagram shows a quadrilateral with some sides extended. Work out the value of a.

    • 220
    • 140
    • 40
    • 60
    Check

12. 12. In the diagram, AE and BD are straight lines that cross at C. Are AB and DE parallel?

    • Yes
    • No
    Check

13. 13. In the diagram, AE and BD are straight lines that cross at C. Do triangles ABC and CDE have angles of the same size?

    • Yes
    • No
    Check