Find each angle measure in the regular polygon

A: 108 degrees
B: 150 degrees
C: 120 degrees
D: 128 4/7 degrees

Element x decays radioactively with a half life of 8 minutes. if there are 450 grams of element x, how long, to the nearest tenth of a minute, would it take the element to decay to 37 grams?

1-for what value of x is line a parallel to line b 2-for what value of x is line a parallel to line b

Given abc find the values of x and y. in your final answer, include all of your calculations.