Find the area of an isosceles triangle. Angle C = 60 degrees. Lateral side 10cm.

Regardless of whether the angle C = 60 ° is the angle at the apex or at the base of an isosceles triangle, in any case, the other angles of the triangle will also be 60 ° (since the sum of the angles in a triangle is always 180 °). If all angles in a triangle are equal, then the triangle is equilateral (all sides are the same). The area of an equilateral triangle is found by the formula:

S = a²√3 / 4;

S = 10²√3 / 4;

S = 100√3 / 4;

S = 25√3 cm².

Answer: 25√3 cm²