Question

Find the value of x.

Answer 1

Answer:

x = 10

Step-by-step explanation:

Look at the picture.

Use the Pythagorean theorem to calculate y:

$y^2+8^2=12^2$

$y^2+64=144$          subtract 64 from both sides

$y^2=80\to y=\sqrt{80}$

Two smaller triangles are similar. Therefore the sides are in proportion:

$\dfrac{x}{y}=\dfrac{y}{8}$           cross multiply

$y^2=8x$       substitute y² = 80

$80=8x$               divide both sides by 8

$x=10$