Lateral Area of a Cone Calculator πrl. Radius Slant height Lateral area 89.535 Step-by-step with your numbers: 1. Values used: 2. Radius = 3 3. Slant height = 9.5 4. Lateral area = 89.535 Did we solve your problem today? 👍 Yes 👎 No Thanks for the feedback! Curved side only. FAQ Total? Add πr² for the base. Related calculators Cone Calculator Find a cone's volume, slant height and surface area. Surface Area of a Cone Calculator SA = πr(r + l). Surface Area of a Cylinder Calculator SA = 2πr(r+h).