A right triangle.
∆ = angle in my explanation.
All the angles in a triangle add up to 180°. This means in this triangle m∆A + m∆B + m∆C = 180°.
Substitute what you have and it becomes x + 2x + 3x = 180°. Add the like terms, and then 6x = 180°. Divide by 6, and we have x = 30°.
Now that means m∆A = 30°, m∆B = 2(30) or 60°, and m∆C = 3(30) or 90°.
A 90° angle is a right angle, so therefore, the triangle classified by it's angle(s) is a right triangle.
No problem!
:D
