In the figure, ABCD is a rectangle. Find the area of the shaded region.
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 145.5 cm2
The shaded region is the rectangle minus the white figure inside it. The white figure has two vertical sides, 4 cm and 5 cm, both at right angles to the 5 cm base, so it is a trapezium whose parallel sides are 4 cm and 5 cm and whose height is the 5 cm base.
Area of rectangle ABCD \(=14\times12=168\,\mathrm{cm^2}\)
Area of the trapezium \(\displaystyle =\frac{1}{2}\times(4+5)\times5=22.5\,\mathrm{cm^2}\)
Shaded area \(=168-22.5=145.5\,\mathrm{cm^2}\)