40 pts! please answer asap!
∠A and ∠B are supplementary angles. The measure of ∠A is three time the measure of ∠B.
Part A: Write an equation to represent the supplementary angle relationship between ∠A and ∠B.
Part B: Use the equation to find the measures of ∠A and ∠B.

Identify all the cases where non-probability sampling is used when attempting to study the characteristics of a large city. studies on every subject in the population divide a population in groups and obtain a sample studies with a limited amount of time demonstrate existing traits in a population studies with the nth person selected