Geometry
Practice:
Solve each.
1. The area of a circle is 30in
2
. If you triple the circle’s radius, what will its new area be?
2. When a hexagon has 2-inch sides, its area is about 10.4in
2
. What will be the approximate
area of a hexagon whose sides are 10 inches long??
3. A rectangular prism has a volume of 17cm
2
. If you double the length and width, but leave
the height unchanged, what will be the volume of the new prism?
4. If you want to double the area of a square, by what percent should you increase the length
of its sides.
hint: Try using a 10-inch square, double its area, and find the length of the sides of the new
square.
5. The volume of the regular dodecahedron below with an edge length of 4-inches is about
490 in
3
. What would be the volume of a regular dodecahedron whose edges are a foot long?
6. The volume of a cone is 3in
3
. What would be the volume after each modification below?
(each part refers to the original figure).
a. Double the radius only. ________________
b. Triple the height only. ________________
c. Double the height and triple the radius. _______________
d. Increase the height and radius by 50%. _______________
7. If you want to double the volume of a cube, by what percent should you increase the
edge length?
a.20% b.23% c.26% d.30% e.40%
Changing Dimensions
Name________________________ Period _____