GEO 4­15­13.notebook
April 15, 2013
FINAL REVIEW
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GEO 4­15­13.notebook
April 15, 2013
Geometry
4/15/13
11.3, Perimeters and Areas of Similar figures
Find the perimeter and area of each regular hexagon.
6 cm
18 cm
Think! I know you can do this!
1. What is the ratio of the side lengths of the smaller hexagon to the
larger hexagon?
2. What is the ratio of the perimeters of the smaller hexagon to the larger
hexagon?
3. What is the ratio of the areas of the smaller hexagon to the larger
hexagon?
4. Draw as many conclusions as you can based off the ratios from #1,2,3.
Areas of Similar Polygons:
If two polygons are similar with the lengths of corresponding sides in the ratio of a:b, then the ratio of their areas is a2:b2. Example 1:
The ratio of corresponding sides of two similar hexagons is 3:2.
a. Find the ratio of their perimeters.
b. Find the ratio of their areas.
Example 2:
Two similar polygons have perimeters 7cm and 28cm
respectively. Find the area of the smaller figure if the area
of the larger is 48cm2.
Example 3: TRUE OR FALSE?
1. Tripling the side length of a square, triples the area.
2. Any two regular polygons with the same number of sides
are similar.
3. Two rectangles with the same area are always similar.
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