In triangle abc, the measure of angle b is 20 more than three times the measure of angle a. the measure of angle c is 55 more than the measure of angle a. find the measure of each angle

Let x be the degree of angle a. 

Angle b: 20+3x
Angle c: 55+x 

We know that all angles add up to 180 degrees. 

180=x+(20+3x)+(55+x) 
180= 5x+75 
180-75=5x 
105/5=x
21=x 

Angle a: 21 degrees 
Angle b: 20+3(21) => 83 degrees 
Angle c: 21+55 => 76 degrees 

Hope I helped :) 

She should use 12/3 to measure