What is the length of ac¯¯¯¯¯ ? enter your answer in the box.

The partial circles at A and C mean those two angles are identical.

Because those two angles are identical sides AB and CB are the same length.

We can set those two equations to equal each other to solve for x:

x+4 = 3x-8

Add 8 to each side:

x+12 = 3x

Subtract 1x from each side:

12 = 2x

Divide both sides by 2:

x = 12/2

x = 6

Since AC is given as X, the length is 6

2. angles qrt and qst both measures 156 degrees.

step-by-step explanation:  

we have been given a diagram of a circle and we are told that measure of arc qvt is 156 degrees.  

we can see from our given diagram that angle qrt and angle qst subtends to arc qvt.

since we know that angles subtended by the same arc at the circumference are always equal.

by angle subtended by same arc theorem, measure of angle qrt and angle qst will be equal to the measure of arc qvt.

therefore, angles qrt and qst both measures 156 degrees and 2nd statement is the correct choice.