Learning Targets I can identify similar polygons. I can write similarity statements. I can find missing parts of similar figure.

Vocabulary similar figures – have the same shape but not necessarily the same size scale factor – the ratio of corresponding linear measurements of two similar figures scale drawing – a drawing in which all lengths are proportional to corresponding actual lengths

Scale and Ratio Examples Real World Scale and Ratio Examples

http://www.youtube.com/watch?v=a0fJUPU5xys

Similar Polygons corresponding parts similarity statement

Example 1

Example 2 Find corresponding sides by locating congruent angles. EA = 12 = 2 ED = 12 = 2 AB = 18 = 2 DC = 18 = 2 ED = 12 = 2 ST 6 1 TU 6 1 RS 9 1 VU 9 1 TU 6 1 YES, The polygons are similar. ABCDE ~ SRVUT, the scale factor is 2:1.

Example 3

Example 4 12 x Begin by writing a ratio involving the variable. 20 10 Choose two corresponding parts that have values (numbers). Create a proportion and solve for the variable. 20 = 12 10 x 20x = 120 x = 6