geometry word problem

Question

if triangle abc the measure of angle b is 21 degrees less than the mesure of angle a multiplied by 4 the mesure of angles c is 1 degree more than the mesure of angle a multiplied by 5 determine the mesure of each interior angle and each exterior angle od of triangle abc

Answer 1

Let x = the measure of ∠a

Let 4x - 21 = the measure of ∠b

Let 5x + 1 = the measure of ∠c

x + 4x - 21 + 5x + 1 = 180

10 x -20 = 180

10x = 200

x = 20º
4x - 21 = 59º

5x + 1 = 101º

 

The exterior angles are supplementary to their interior angles. You can probably find those.