Respuesta :

Answer:

D. 7.5 inches

Step-by-step explanation:

So, we can find the ratio of the big triangle to the small one by dividing the values of the hypotenuse.

So, 18/6 = 3

Big:small = 3:1

So, using this we can make an equation to find AD.

Let's say ED=x.

AD is basically ED (x) + AE (5).

Since ED is part of the small triangle, and AD is part of the big one, we can use the 3:1 ratio from above.

So, [tex]\frac{x+5}{x}[/tex]=3.

Multiply both sides by x, getting x+5 = 3x.

Subtract the x:                            -x        -x

And you get 5=2x, giving you 2.5 = x.

However, we're not done yet, as 2.5 is the value of ED, but we need AD.

Remember, AD is = ED + AE.

So, AD = 2.5 + 5.

Finally, AD =  7.5