Area of a Triangle: Using variables

Given the rectangle ABCD

Given BC=X and the side AB is larger by 4 cm than the side BC.

The area of the triangle ABC is 8X cm².

What is the area of the rectangle?

Let's calculate the area of triangle ABC:

$8x=\frac{(x+4)x}{2}$

Multiply by 2:

$16x=(x+4)x$

Divide by x:

$16=x+4$

Let's move 4 to the left side and change the sign accordingly:

$16-4=x$

$12=x$

Now let's calculate the area of the rectangle, multiply the length and width where BC equals 12 and AB equals 16:

$16\times12=192$

192

The area of the triangle is 9.

Calculate X.

6

The area of the triangle below is equal to 21.

Calculate X.

6

Since the area of the triangle is equal to 15.

Find X.

6

The area of the triangle is equal to 18.

Calculate X.

6

The area of the triangle is 16.

Calculate X.

8

Since the area of the triangle is equal to 15.

Find X.

10

The area of the triangle below is equal to 3.

Calculate X.

3

The area of the triangle is 12.

Calculate X.

8

Calculate X using the data in the figure below.

3

Look at the triangle ABC below.

BC = 6

AD = X

Express the area of the triangle using X.

Answers B and C are correct.

Express the area of the triangle ABC in terms of X.

$\frac{X+9}{2}\sqrt{3X^2-2X-1}$