Question

the angle of a triangle are in the ration 3:4:5. find the measure of each of the triangle

Answer 1

let the angle be x
therefore 3x+4x+5x = 180 degree
12x = 180
x = 180/12
x = 15
3x = 3*15 = 45
4x = 4*15 = 60
5x = 5*15 = 75

Answer 2

let the angles be 3x,4x,5x resp.

3x + 4x+5x = 180
12x=180
x=180/12
x=15

now 
3x= 3×15=45
4x=4×15=70
5x=5×15=75

therefore the angles of the  triangle are 45°,70°,75° respectively