1) 180°. All the interior angles in a triangle ALWAYS add to 180°.
2) x = 60°. As stated in 1), all angles in a traingle add to 180° so knowing this, x = 180 - 70 - 50 = 60°.
3) <A = 90, <B = 60, <C = 30. Knowing that all angles in a traingle add to 180, we can make an equation. 6x + 4x + 2x = 180 or 12x = 180. This means x is 15°. Now we just need to multiply it. 6x = 90, 4x = 60 and 2x = 30.