Arc length formula: n*3. 14*R/360, where n is the degree of the central angle of the required arc and r is the radius of the circle.

Lateral area of the cone: 2 * 3.14 * r * l/2 = 3.14r * l where r is the radius of the base circle and l is the length of the side of the cone.

Total area of the cone: 3.14r * l+3.14 * r * r = 3.14 * r * (r+l).