Area of A Cone

Area of A Cone Cone is a geometric figure with a fixed vertex and a circular base. The curved surface area of the cone = * r * s. Here r is the radius and s is the length of the slant side. Slant side, s = (r2+h2). The height h of the cone from the vertex of the cone and the radius r of the circular base make a right angle. Example 1: What is the curved surface area of the cone which has the base radius r of 3 cm and height 4 cm? The base radius of the given cone is 3 cm, i.e. r = 3 cm. The height of the cone, h = 4 cm. The slant height of the cone, s = (r2 + h2). s = (32 + 42) = (9 + 16) = 5cm . Area of cone = * r *s This makes the solution = 3.14 * 3 * 5 = 47.1 cm2 Hence, curved surface area = 47.1 cm2 approximately. Example 2: What is the curved surface area of the cone which has the base radius r of 5 cm and height 12 cm? The base radius of the given cone is 5 cm, i.e. r = 5 cm. The height of the cone, h = 12 cm. The slant height of the cone, s = (r2 + h2). s = (52 + 122) = (25 + 144) = 13 cm . Area of cone = * r *s This makes the solution = 3.14 * 5 * 13 cm2 = 204.1 cm2 Hence, curved surface area = 204.1 cm2 approximately.