Perimeter and Area of Similar Polygons

What is the ratio of the perimeters of two similar figures?

• Ratio of corresponding side lengths

• Ratio of volumes.

• Ratio of areas.

• Ratio of corresponding angles.

Three sides of a triangle are 12, 16, and 22. The biggest side of another similar triangle is 176. What is the perimeter of the bigger triangle?

• 320

• 360

• 400

• 440

• Perimeter:  $\frac{4}{9}$     ; Area:  $\frac{2}{3}$ 

• Perimeter:  $\frac{2}{3}$    ; Area:  $\frac{2}{3}$  

• Perimeter:  $\frac{4}{9}$     ; Area:  $\frac{4}{9}$  

Find the ratios (red to blue) of the perimeter and the area.

• Perimeter: 20/54
  Area: 58/485
  Area:

• Perimeter: 3/4
  Area: 9/16

• Perimeter: 58/299
  Area: 57/383

• Perimeter: 5/10
  Area: 19/46

The triangles are similar and the perimeter of SRT = 15. What is the scale factor between the two?

• ⅘

• ⅚

• ½

• ¾

Find the perimeter of the large triangle.

• 24

• 36

• 12

• 54

△BNV ~ △BRG, BR = 4x + 7, and BG = 6x - 12. Find the perimeter of △BRG.

Find the perimeter of the large triangle.

• 24

• 36

• 12

• 54

Answer explanation

Remember.... the ratio of the perimeters of similar figures is THE SAME as the ratio of the side lengths of similar figures!

If the ratio of corresponding sides in two similar polygons is 1:2, and one side of the first polygon is 10 units, what is the length of the corresponding side in the second polygon?

• 20

• 30

• 15

• 5

Find the perimeter of the large triangle. (First find the missing side length)

• 24

• 36

• 12

• 54