Question

if the height of the parallelogram shown is increased by 1 cm and the base is increased by 2 cm, what is the area of the new parallelogram?
5 cm
4 cm
9 cm
28 cm²
39 cm²
55 cm²
60 cm²

Explanation:

Step1: Calculate new height and base

Original height \(h = 4\mathrm{cm}\), new height \(h_{new}=4 + 1=5\mathrm{cm}\).
Original base \(b = 9\mathrm{cm}\), new base \(b_{new}=9+ 2 = 11\mathrm{cm}\).

Step2: Use area formula for parallelogram

The area formula of a parallelogram is \(A=b\times h\).
Substitute \(b = 11\mathrm{cm}\) and \(h = 5\mathrm{cm}\) into the formula: \(A=11\times5\).
\(A = 55\mathrm{cm}^{2}\)

Answer:

\(55\mathrm{cm}^{2}\) (the third option)