The lateral surface of a cylinder can be found with the equation
A = 2 π r h Substitute in your values. A = 2 π (11) (7) Multiply 11 and 7. A = 2 π (77) Multiply 77 and 2. A = 154π Don't simplify anymore so you can keep pi in the answer.
The surface are uses the equation
A = 2 π r h + 2 π r² Substitute in your values. A = 2 π (11) (7) + 2 π (11)² Simplify and multiply your terms. A = 2 π (77) + 2 π (11)² A = 154 π + 2 π (11)² A = 154 π + 2 π (121) A = 154 π + 242 π Since both terms are in terms of pi, you can combine them. A = 396π Stop simplifying to leave the answer in terms of pi.