Find the area of a parallelogram ABCD in which AB = 60cm, BC = 40cm and AC = 80 cm. [Given: = 3.87]
Let the sides of the triangle ABC be:
a = 40 cm, b = 80 cm and c = 60 cm
∴ s =
=
=
= 90 cm
Now, by using Heron’s formula we get:
Area of
=
=
=
= 30 × 10
= 300 × 3.87
= 1161 cm2
As we know that, the diagonal of a parallelogram divides it into two triangles of equal areas
∴ Area of parallelogram (ABCD) = 2 × Area of ()
= 2 × 1161
= 2322 cm2