math
posted by thomas .
In triangle ABC, angle B = 3, angle A and angle C = 8 angle A. How many degrees are there in angle B ?
a. 15 degree
b. 30 degree
c. 45 degree
d. 60 degree
e. 120 degree
please answer and explain

the sum of the angles in a triangle is 180 degrees.
A+3A+8A=180
12A=180
A=15
B=3A=45 deg