Question

The area of a trapezium is 138 m2. The distance and the difference between the
lengths of the parallel sides are 12 m and 7 m respectively. Find the lengths of
the parallel sides.
​

Answer 1

Answer:

8 m and 15 m

Step-by-step explanation:

Let parallel sides be a and b respectively

Area = 1/2 × height × sum of parallel sides

A = 1/2 h(a+b)

We know that

h = 12 m

b - a = 7 m therefore b = a + 7

A = 138 m^2

Using Area:

138 = 1/2 × 12 × (a+b)

a+b = 138/6

a + b = 23

Replacing b:

a + a + 7 = 23

2a = 16

a = 8

b = a + 7

b = 8 + 7 = 15