Given a triangle ABC, the outer angle at apex B is 120 degrees. Find angle A and angle C if angle A is 2 times the angle C

Let the angle C be determined by us through the variable n.

Therefore, according to the conditions of our task, the angle A can be represented by us using the mathematical expression 2n.

But after all, from the conditions of this task, we know for sure that the external angle at the vertex B (and hence the sum of these angles) is 120 °, therefore, we can write down the equation and find out what the sought angles will be equal to:

2n + n = 120;

3n = 120;

n = 40;

2 * 40 = 80.

Answer: Under these conditions, the angle A is 80 °, and the angle C is 40 °.