I need help ASAP, would really appreciate it

What are the measures of ∠a, ∠b, ∠c and ∠d? explain how to find each of the angle measure.

How do you determine whether a relationship represented as as graph is linear or nonlinear

In a certain city, the hourly wage of workers on temporary employment contracts is normally distributed. the mean is $15 and the standard deviation is $3. what percentage of temporary workers earn less than $12 per hour? a. 6% b. 16% c. 26% d. 36%