Question

4. A parallelogram has sides 34 cm and 20 cm. One of
its diagonals is 42 cm. Calculate its area.
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Answer 1

Answer:

Area = 672

Explanation:

First we find s ( 1/2 the perimeter )

s = (1/2)*(34 + 20 + 42)

s = (1/2)*(96)

s = 48

The formula for the area A is A = sq-rt(s*(s-a)(s-b)(s-c))

so A = sq-rt( 48 * (48-34) * (48-20) * (48-42) )

A = sq-rt( 48 * 14 * 28 * 6 )

A = sq-rt( 112896 )

A = 336

The area of the parallelogram is twice 336 = 672