Answer:
D. 7.5 inches
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,
=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