1. Course 2 9-4 Area of Triangles and Trapezoids AREA OF A TRIANGLE h b A = 1212 bh The area A of a triangle is half the product of its base b and its height h.

2. Course 2 9-4 Area of Triangles and Trapezoids AREA OF A TRAPEZOID h b1b1 A = 1212 h(b 1 + b 2 ) The area of a trapezoid is half its height multiplied by the sum of its two bases. b2b2 In the term b 1, the number 1 is called a subscript. It is read as “b-one” or “b sub-one.” Reading Math

3. Course 2 9-2 Perimeter and Circumference Radius Diameter Circumference C = d, or C = 2r CIRCUMFERENCE OF A CIRCLE The circumference C of a circle is  times the diameter d, or 2  times the radius r.

4. SURFACE AREA OF A PRISM The surface area of a rectangular prism is the sum of the areas of each face. S = 2lw + 2lh + 2wh

5. SURFACE AREA OF A CYLINDER The surface area S of a cylinder is the sum of the areas of its bases, 2r 2, plus the area of its lateral surface, 2rh. S= 2r 2 + 2rh

6. The volume of a rectangular prism is the area of its base times its height. This formula can be used to find the volume of any prism. VOLUME OF A PRISM The volume V of a prism is the area of its base B times its height h. V = Bh

7. Finding the volume of a cylinder is similar to finding the volume of a prism. VOLUME OF A CYLINDER The volume V of a cylinder is the area of its base, r 2, times its height h. V = r 2 h

8. In fact, the volume of a pyramid is exactly one- third the volume of a prism if they have the same height and same-size base. The height of a pyramid is the perpendicular distance from the pyramid’s base to its vertex. Course 2 10-3 Volume of Pyramids and Cones

9. The volume of a cone is one-third the volume of a cylinder with the same height and a congruent base. The height of a cone is the perpendicular distance from the cone’s base to its vertex. Course 2 10-3 Volume of Pyramids and Cones