Find AC if a = 18. The angle measure is 60 degrees as seen in the picture

36

Step-by-step explanation:

With a transversal, the alternate angles will be congruent. For example, angles BCA and CAD will both be 60 degrees.

Knowing this, that means angles DCA and BAC will be 30 degrees because the angles in a triangle add up to 180 degrees.

This means both triangles are 30 60 90 triangles, so we can find AC by using the special right triangle patterns.

In a 30 60 90 triangle, the hypotenuse (AC) is twice of the length of the short leg (a)

So, multiply 18 by 2, since a = 18:

18(2)

= 36

AC = 36