Find the third corner of a triangle if its two angles are equal a) 42 and 54 B) 48 and 80?

A triangle is a geometric figure consisting of three points that lie on one straight line, connected by segments.

The sum of all the angles of the triangle is 180º:

∠А + ∠В + ∠С = 180º.

In this way:

1) if the angle ∠А is equal to 42º, and the angle ∠Б is equal to 54º, then:

∠С = 180º – ∠А – ∠В;

∠С = 180º – 42º – 54º = 84º.

2) if the angle ∠А is equal to 48º and the angle ∠Б is equal to 80º, then:

∠С = 180º – ∠А – ∠В;

∠С = 180º – 48º – 80º = 52º.

Answer: in the first variant the angle ∠С is equal to 84º, in the second variant the angle ∠С is equal to 52º.