In the figure, PQST is a parallelogram and TSR is a straight line. If the…

In the figure, PQST is a parallelogram and TSR is a straight line. If the area of (bigtriangleup)QRS is 20cm², find the area of the trapezium PQRT.

Correct Answer: Option C

Explanation

A_{(bigtriangleup)} = (frac{1}{2}) x 8 x h = 20
= (frac{1}{2}) x 8 x h = 4h
h = (frac{20}{4})
= 5cm
A_{(bigtriangleup)}(PQTS) = L x H
A_{(bigtriangleup)PQRT} = A_{(bigtriangleup)QSR} + A_{(bigtriangleup)PQTS}
20 + 50 = 70cm²
ALTERNATIVE METHOD
A_{(bigtriangleup)PQRT} = (frac{1}{2}) x 5 x 28
= 70cm²