Find Side Length of a Square: Area 25 in Similar Squares Problem

Question

The two squares above are similar.

If the area of the small square is 25, then how long are its sides?

00:00 Find the length of the small square's side

00:03 Let's mark each square with numbers 1,2

00:07 Let's use the formula for calculating square area (side squared)

00:14 Let's mark the square's side as X

00:18 Let's substitute in the area formula and solve for X

00:23 And this is the solution to the problem

The area of the large square is:
$10^2=100$

The area of the small square is 25.

$\frac{100}{25}=4$

The square root of 4 is equal to 2.

We will call X the length of the side:

$\frac{10}{x}=2$

$2x=10$

$x=5$