← Back to the activity

Class 9 Maths — Areas on the same base

Use the fact that figures on the same base and between the same parallels have equal areas.

Name: ________________________

  1. 1.Two triangles stand on the same base and between the same parallels. One has an area of 25 square centimetres. What is the area of the other, in square centimetres?

  2. 2.A triangle has a base of 12 cm and a height of 7 cm. What is its area, in square centimetres?

  3. 3.All four triangles have bases of the same length on the lower line, and three of them have their tips on the upper line. Tap the triangle with the smallest area.

    Write the number of the part.

    1234

  4. 4.A median splits a triangle into two smaller triangles of 18 square centimetres each. What is the area of the whole triangle, in square centimetres?

  5. 5.Each triangle's base and height are given in centimetres. Match it to its area in square centimetres.

    • base 10, height 6
    • base 8, height 5
    • base 12, height 9
    • base 7, height 4
    • base 14, height 6
    • 30
    • 54
    • 20
    • 42
    • 14

  6. 6.Two parallelograms on the same base and between the same parallels always have...

    • a) equal areas
    • b) equal diagonals
    • c) equal perimeters
    • d) the same shape

  7. 7.A parallelogram has an area of 96 square centimetres on a base of 16 cm. What is its height, in centimetres?

  8. 8.A triangle and a parallelogram stand on the same base and between the same parallels. The parallelogram's area is 60 square centimetres. What is the triangle's area, in square centimetres?

Answer key — Class 9 Maths — Areas on the same base

  1. 1. 25
  2. 2. 42
  3. 3. 3 — The third triangle
  4. 4. 36
  5. 5. base 10, height 6 → 30; base 8, height 5 → 20; base 12, height 9 → 54; base 7, height 4 → 14; base 14, height 6 → 42
  6. 6. a) equal areas
  7. 7. 6
  8. 8. 30