Two angles of a triangle are 30°and 80°. Find the third angle.

The third angle of the triangle is 70°.

Step-by-step explanation:

The two angles of a triangle (say Δ ABC) are given to be 30° and 80°.

We have to find the third angle.

Let us assume that ∠ A = 30° and ∠ B = 80°, then we have to find ∠ C.

Now, we know that, ∠ A + ∠ B + ∠ C = 180° {Property of a triangle}

⇒ 30° + 80° + ∠ C = 180°

⇒ ∠ C = 180° - 30° - 80° = 70°

Therefore, the third angle of the triangle is 70°. (Answer)