Question

PLEASE HELP! What is AD? A. 15 B. 12 C. 3 D. 20

Answer 1

Answer:

A. 15

Step-by-step explanation:

To solve this you need to compare the lengths given to you in the question statement.

Because the lines originate from a single point, they're like triangles.  We can easily see a triangle AGF and a triangle ADE, right?

Both triangles are similar triangles, so we can see triangle ADE as a larger version of angle AGF.

They give you the dimension of A F and A E (through A F + F E) to establish a ratio... and they give you A G, asking for A D.

So, A F = 16, A E = 20 (16 + 4), A G = 12.

Since A D is to A G what A E is to A F, we can easily make the following cross-multiplication:

$\frac{A D}{A G} = \frac{A E}{A F}$

So, A D = (A G * A E)/A F

A D = (12 * 20) / 16 = 15