1. Perimeter and Area of Similar Figures
Sec 5. 3-B pg

2. Similar Figures A B C Z
49
90
41 3 4 5 10 8 6 X Y
Corresponding Sides – AB and XY, BC and YZ, and AC and XZ are sides that are in the same relative position. Corresponding sides are in proportion.
Corresponding Angles - A and X, B and Y and C and  Z are angles that are in the same relative position. Corresponding angles are congruent.

3. Similar Figures – Find PerimeterB C Z 3 6
𝐴𝐵 𝑋𝑌 = 6 3 , so X Y
6 3 = 𝑃 𝐴𝐵𝐶 𝑃 𝑋𝑌𝑍
6 3 = 𝑃 𝐴𝐵𝐶 12
Given the perimeter of Triangle XYZ is 12, what is the perimeter of Triangle ABC?
Perimeters of similar figures are proportional
3PABC = (6)(12)
3 𝑃 𝐴𝐵𝐶 3 = 72 3
PABC = 24

4. GIVEN SIMILAR FIGURES, find area.
Pentagon ABCDE is similar to Pentagon PQRST. Find the area of Pentagon ABCDE if the area of Pentagon PQRST is 20 square inches. P A
𝐴 𝐴𝐵𝐶𝐷𝐸 = 𝐴 𝑃𝑄𝑅𝑆𝑇 ∗ 𝑆𝑐𝑎𝑙𝑒 𝐹𝑎𝑐𝑡𝑜𝑟 2 2 6 T Q
𝐴 𝐴𝐵𝐶𝐷𝐸 = 20 in.2 * 9 B E S R
𝐴 𝐴𝐵𝐶𝐷𝐸 = 180 in.2
Areas of similar figures
are proportional to the
square of the scale factor. D C
6 2 = 3 1
32 = 9