SOLUTION: In triangle​ ABC, the size of angle B is 4 times the size of angle​ A, and the size of angle C is 1 degrees less than 5 times the size of angle A.

Algebra ->  Angles -> SOLUTION: In triangle​ ABC, the size of angle B is 4 times the size of angle​ A, and the size of angle C is 1 degrees less than 5 times the size of angle A.      Log On


   

Question 1122368: In triangle​ ABC, the size of angle B is 4 times the size of angle​ A, and the size of angle C is 1 degrees less than 5 times the size of angle A.
Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
angle B = 4 * angle A
angle C = 5 * angle A - 1
angle A + angle B + angle C = 180 becomes:
angle A + 4 * angle A + 5 * angle A - 1 = 180
combine like terms to get 10 * angle A - 1 = 180
add 1 to both sides fo the equation to get:
10 * angle A = 181
divide both sides of the equation by 10 to get:
angle A = 181 / 10
solve for angle A to get:
angle A = 18.1 degrees.
angle B = 4 * angle A = 72.4 degrees.
angle C = 5 * angle A - 1 = 89.5 degrees.
18.1 + 72.4 + 89.5 = 180 degrees = sum of the interior angles of triangle ABC.
your solution appears to be:
angle A = 18.1 degrees
angle B = 72.4 degrees
angle C = 89.5 degrees