In the diagram, PQST and QRST are parallelograms. Calculate the area of the trapezium PRST.

A.
60cm^{2} 
B.
50cm^{2} 
C.
40cm^{2} 
D.
30cm^{2}
Correct Answer: Option D
Explanation
PR = 4 + 4 = 8 cm
Area of trapezium = (frac{1}{2} (a + b) h)
= (frac{1}{2} (4 + 8) times 5)
= 30 cm(^2)