Question

Question 7

The length of one side of a rectangle is 12 cm.
The length of the diagonal of the rectangle is 13 cm.
Calculate the area of the rectangle.

Answer 1

Area = 60 cm^2

Explanation:

Remark

It's a rectangle. So the diagonal divides the rectangle into 2 congruent right angle triangles. You can use Pythagoreas

Givens

c = 13 cm

a = 12

b = ?

Formula

a^2 + b^2 = c^2

Area = L * w

Solution

12^2 + b^2 = 13^2

144 + b^2 = 169 Subtract 144 from both sides

b^2 = 169 - 144

b^2 = 25 Take the square root of both sides.

sqrt(b^2) = sqrt(25)

b = 5

Find the area of the rectangle

Area = L * w

L = 12

w = 5

Area = 12 * 5

Area = 60