Calculate ED Length When ED = 1/3 AB in Rectangle with Area 45

Question

The area of the rectangle below is equal to 45.

$ED=\frac{1}{3}AB$

Calculate the size of ED.

00:00 Find ED

00:03 The formula for calculating rectangle area - length (AC) multiplied by width (AB)

00:10 Let's substitute appropriate values and solve for AB

00:20 According to the given data, ED equals one-third of AB

00:24 And this is the solution to the problem

The area of rectangle ABCD equals length times width.

Let's write down the known data in a formula to find side CD:

$45=5\times CD$

Let's divide both sides by 5:

$CD=9$

We know that in a rectangle, each pair of opposite sides are equal, therefore:

$AB=CD=9$

Since we are given that ED equals one-third of CD, we can substitute the known data and calculate side ED:

Remember that AB equals CD

$ED=\frac{1}{3}AB=\frac{1}{3}\times9=3$