In a triangle ABC, BC = 12, AC = 16 and angle C = 60°. Find the area of the given triangle ABC. 2. The sides of a triangle ABC are a = 12, b = 10 and c = 18. Find the area of a triangle ABC and lengths of the three altitudes of the given triangle.
3. One side of an equilateral triangle is 15 units long. Find the inradius r and circumradius R of this triangle.