# How do you find the area of the rectangle given the side of it is 3-√10 the bottom is 4√10?

Jun 7, 2016

120 square units

#### Explanation:

The area of a rectangle is A = lb , where l , is the length and b , the breadth.

here $l = 4 \sqrt{10} \text{ and } b = 3 \sqrt{10}$

$\Rightarrow A = 4 \sqrt{10} \times 3 \sqrt{10} = 4 \times 3 \times \sqrt{10} \times \sqrt{10}$

Note: in general $\sqrt{a} \times \sqrt{a} = a$

$\Rightarrow \sqrt{10} \times \sqrt{10} = 10$

$\Rightarrow A = 4 \times 3 \times 10 = 12 \times 10 = 120 \text{ square units}$