Question

pqrs is a trapezium with pq parallel to sr and pq= 7cm , qr = 4cm and rs = 4cm . If the block is 12cm long , its volume is ?

Answer 1

You don't give any way to calculate the height of PQRS. It could be anywhere from √7 to 4. So let's call it h.
Then the volume is just (4+7)/2 * h*12 = 66h cm^3