In a triangle, the two angles are 43 and 56 degrees. How many degrees is the third angle of the triangle?

Given:

Triangle.

∠1 = 43 degrees.

∠2 = 56 degrees.

Find: ∠3.

The sum of the angles of a triangle is 180 degrees (by the property of a triangle). Hence:

∠1 + ∠2 + ∠3 = 180⁰.

43⁰ + 56 ⁰ + ∠3 = 180⁰.

99⁰ + ∠3 = 180⁰.

∠3 = 180⁰ – 99⁰.

∠3 = 81⁰.

You can solve a given problem in the form of an expression:

180⁰ – (43⁰ + 56⁰) = 180⁰ – 99⁰ = 81⁰.

Answer: 81 degrees is the third corner of the triangle.