Question

find the perimeter of the rectangle whose length is 12 cm and a diagonal is 15 cm

Answer 1

Answer:

42 cm

Step-by-step explanation:

Let us assume a triangle inside a rectangle.

Hypotenuse = Diagonal

Base = Length

Height = Breath

Diagonal = $\sqrt{{Length}^{2}+{Breadth}^2}$

$15 = \sqrt{{12}^{2}+{b}^2}$

$15 = \sqrt{144+{b}^{2}} \\\\{15}^{2} = 144+{b}^{2}\\225 = 144+b^{2}\\\\81 = b^{2}\\b = \sqrt{81} = 9 cm$

Perimeter of the rectangle = $2(l+b)$

= $2(12+9)\\= 2*21\\= 42 cm$

Answer 2

12+15x2= 42 so perimeter of rectangle is 42cm