What is the length of ab?

a. 6
b. 4
c. 2
d. 8

Since the sides are equal to each other, (as you can see; the angles are both 63 degrees) the sides will be too!

Have the equations set to each other. 

3x=4x-2    (they are equal to each other)

Subtract 4x from both sides. 

-1x=-2

Divide each side by -1.

x=2

Plug in 2 in one of the equations. 

3(2)= 6

Both of the sides are equal to 6. 

I hope this helps! 

The answer is part a: use