How do u find the area of a trapezium if all the sides are given?

Question

How do u find the area of a trapezium if all the sides are given?

Answer 1

This does not seem as easy as it looks.

suppose you say a and b are the parallel sides with a>b and c and d are the other sides.

First cut the two triangles off the two ends so you have an oblong left which has area b*h (h being the distance between the parallel sides).

Combine the two triangles so that you have a triangle with sides c,d and (a-b). use the semi-perimeter formula to calculate the area of this triangle call it A.

Now you can find the distance h as h=2A/(a-b).

so the total area = A+b*h

Answer 2

Let a and b be parallel sides

h is perpendicular height

A = (1/2) (a + b) h