Calculate Rectangle Perimeter: Triangle Perimeter = 20 with Side X+2

Question

Look at the following rectangle:

Given that the perimeter of the triangle BCD is 20, what is the perimeter of the rectangle ABCD?

00:07 Let's begin by finding the perimeter of the rectangle.

00:13 To find a triangle's perimeter, add up the lengths of all its sides.

00:24 Now, plug in the given values to solve for X. Take your time.

00:41 Great job! Now gather all similar terms together.

00:48 Let's focus on getting X alone on one side of the equation.

00:53 You found the value of X! Next, use this to find the side length.

01:03 Remember, opposite sides in a rectangle are equal.

01:18 To find the perimeter of the rectangle, add up all the sides.

01:23 Substitute in the values you have and calculate the perimeter.

01:42 And there you have it! That's your solution.

Given that the perimeter of triangle BCD is 20

We can therefore insert the existing data and calculate as follows:

$20=10+6+x+2$

$20=16+x+2$

$20-16-2=x$

$x=2$

Now we can calculate the BC side: 2+2=4

Perimeter of the rectangle ABCD:

$6+6+4+4=12+8=20$