Grade A Surface Area Calculate the surface area

Grade A* Surface Area Calculate the surface area of spheres, pyramids, cones and composite solids. If you have any questions regarding these resources or come across any errors, please contact helpful-report@pixl. org. uk

Key Vocabulary Formula Substitute Net Area Surface

How to find the surface area of a shape • Is there a standard formula? OR • Sketch the shape as a NET • Find the area of each of the component parts.

How to find the surface area of a sphere Learn the formula: - r=3 cm

How to find the surface area of a pyramid Sketch the net: Height = 5. 2 cm 10. 4 cm 6 cm 12 cm Can you think of an alternative method?

How to find the surface area of a cone Learn the formula: 8. 1 cm 9 cm Identify r and l r= 4 cm, l=9 cm 8 cm Substitute in to formula:

Practice For these questions, use r=3 cm, h=5 cm and if needed, ‘l’=6 cm Find the surface area of: 1) A tetrahedron, base length of 2 cm. 2) A cone 3) A sphere

Reasoning. Am I Correct? Explain why. “The surface area of the hemisphere is 402. 1 cm 2 to 1 dp” r= 8 cm

Problem Solving and Reasoning The curved surface area of the cone is 250 cm 2. The radius of the base is 6 cm. What is the height of the cone? 3 cm πLx 6=250 250/6 π =L L=13. 26 cm H=12. 9 cm Don’t make the mistake of confusing height (perpendicular to base) with l , which is the diagonal length.

Problem Solving and Reasoning A cone and a hemisphere have the same surface area and the same radius. The cone has a diagonal length of 10 cm. What is the radius of the hemisphere? SA of hemisphere SA of cone