In the figure, PQRS is a rectangle. If the shaded area is 72 sq. cm, find h.

Answer Details

From the diagram, PQRS is a rectangle

Area of shaded part = 72sq.cm

But 72 = 3h - 4 + 6h - 4 + 4h

= 72 - 16h - 8

= 16h - 72 + 8

=16h = 80

h = 8016 $\frac{80}{16}$

= 5cm