The adjacent sides of a parallelogram ABCD measure 34 cm and 20 cm, and the diagonal AC measures 42 cm. Find the area of the parallelogram.
Now in ∆ABC
AB = a = 34 cm, BC = b = 20 cm, AC = c = 42 cm
Let a, b and c are the sides of triangle and s is
the semi-perimeter, then its area is given by:
A = 
where 
=
= 48
A= 
A = 
= 
cm2
Hence, area of Parallelograme ABCD =2× 336 =672 cm2
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