Answer:
The angles are 45°, 60° , 75°
Step-by-step explanation:
<h3>Angle sum property:</h3>Sum of all the angles of a triangle is 180°.
Equation:
3x + 5x + 4x = 180
Combine like terms,
12x = 180
x = 180/12
3x = 3 *15 = 45°
5x = 5* 15 = 75°
4x = 4 *15 = 60°