1. VOLUME of a CONE and UNKNOWN VALUES PRE389 When finding unknown values, plug what you know into the formula and solve for what’s missing! Find the height of the cone. The volume of the cone is 72 m 3. Volume =  r 2 h 72 = (3 2 )h V = Ah A = Area of the base h = height of the solid 1313 3 m h 1313 1313 A circle =  r 2 r = 3

2. VOLUME of a CONE and UNKNOWN VALUES PRE389 3 2 = 9 Plug in what you know. (9) = 3 Divide both sides by 3. 24 = h The height of the cone is 24 meters!! V = Ah A = Area of the base h = height of the solid 1313 72 = (9)h 1313 72 = 3h 1313 The volume of the cone is 72 m 3. 3 m h A circle =  r 2 r = 6 72 = (3 2 )h 1313

3. VOLUME of a CONE and UNKNOWN VALUES PRE389 The volume of the cone is 264 in 3. The height is 22 in. Find the area of the triangular base. The radius is 6 inches!! V = Ah A = Area of the base h = height of the solid 1313 Plug in what you know. Divide both sides by . 264  =  r 2 22 1313 264 = r 2 22 1313 Divide both sides by 22. A circle =  r 2 12 = r 2 1313 Multiply both sides by 3. 36 = r 2 Take sq root of both sides. 6 = r 22 r