The formula to find the measure of an interior angle is

, where

represents the number of sides in the polygon. In this problem,

would represent

.
Let's plug in the value for


Let's simplify that.

Now we know that the <span>measure of an interior angle of a regular three-sided polygon is 60</span>°.
Your answer would be B!Let me know if you have any questions regarding this problem!
Thanks!
-TetraFish
You need to start calculating from the innermost bracket and if there are no signs to do any operation then you need to multiply
Divide each side of the equation by 0.3 .
"The quotient of z and 4"
is the same as saying
"z divided by 4"
z/4
The y-intercept of the line is 40