How to find the angles in an equilateral triangle if one angle is known?

Given:

One of the corners in an equilateral triangle

To find:

All angles in a triangle

Decision:

1) By the theorem on the ratio of sides and angles in a triangle:

Against the larger angle lies the larger side, and vice versa, against the larger side, lies the larger angle.

Since we have an equilateral triangle, all sides are equal, therefore, all angles in our triangle are equal.

In a triangle, there are only 3 angles and in total give 180 °, therefore 180 ° / 3 = 60 ° – each of the angles.

Answer: each angle is 60 °