The angle at the base of an isosceles triangle is 60 degrees. The base is 16 cm. Find the side.

Since the angles adjacent to the base of an isosceles triangle and opposite to its lateral sides are equal to each other, and the sum of the degree measures of all angles of the triangle, as you know, is equal to 180 °, we can find the angle at the apex: 180 ° – 60 ° – 60 ° = 60 ° …

Since all the angles of this triangle are equal to each other, then such a triangle is regular, therefore, its sides have the same length, which means its sides are equal to the base and equal to 16 cm.