**Activity Idea:** Have students describe how to find the diameter or area of a triangle, polygon, circle, cone or sphere using equations.

**Tip: **Use the drawing tool to write down the equation and solve a sample problem. Then use the voice recorder tool to explain how to solve the problem.

**Supports Common Core: **CCSS.MATH.CONTENT.6.G.A.1: Find the area of right triangles, other triangles, special quadrilaterals, and polygons by composing into rectangles or decomposing into triangles and other shapes; apply these techniques in the context of solving real-world and mathematical problems. CCSS.MATH.CONTENT.7.G.B.4: Know the formulas for the area and circumference of a circle and use them to solve problems; give an informal derivation of the relationship between the circumference and area of a circle. CCSS.MATH.CONTENT.8.G.C.9: Know the formulas for the volumes of cones, cylinders, and spheres and use them to solve real-world and mathematical problems.