 Hi and welcome to the session. Let us discuss the following question. The question says curve surface area of a cone is 308 cm2 and its land height is 14 cm. Fine? First part is radius of the base and second part is total surface area of the cone. Now before solving this question we should know the formula for finding the total surface area and curve surface area of a cone. Curve surface area of a cone is equal to pi RL and total surface area of a cone is equal to curve surface area of the cone that is pi RL plus area of the circular base that is pi R square. The knowledge of these two formulae is the key idea in this question. Now begin with the solution. In the first part we have to find the radius of the base. Let R be radius of the base. We are given that curve surface area of cone is equal to 308 cm2. We have learned in the key idea that curve surface area of cone is equal to pi RL. So this implies pi RL is equal to 308. Now substitute the value of pi and L. High is equal to 22 by 7. L is equal to 40 cm. This is equal to 308. Now this implies R is equal to 308 into 7 upon 22 into 40 and this is equal to 7 cm. So radius of the cone is 7 cm. Now in the second part we have to find the total surface area of the cone. We know that total surface area of cone is equal to pi RL plus pi R square. Substitute the value of pi R and L in this. Pi is equal to 22 by 7. R is equal to 7. L is equal to 14 cm. Again pi is equal to 22 by 7. R square is equal to square of 7 cm2 and this is equal to 308 cm2 plus 154 cm2 and this is equal to 462 cm2. Hence the required answer of the first part is 7 cm and for the second part is 462 cm2. This is our required answer. So this completes the session.