Class Notes – Similarity of Polygons
Date ______________
Lesson Goal –
Congruent Polygons –
Similar Polygons –
How Similarity impacts Area.
What is Area?
Compare two squares that have a scale factor of “a” on the side lengths.
1) Are these two polygons similar? Why or why not?
2) 𝑇𝐻𝐼𝑁𝐾 ~𝐿𝐴𝑅𝐺𝐸. 𝑎) 𝐹𝑖𝑛𝑑 𝐴𝐿, 𝑅𝐴, 𝑅𝐺 𝑎𝑛𝑑 𝐾𝑁.
b) The area of LARGE = 75 cm2. What is the area of THINK?
3) Given two 20-sided similar polygons that have side lengths in a ratio of 5 to 9:
a) What is the perimeter of Polygon 2 if perimeter of Polygon 1 = 40 cm.
b) What is the area of Polygon 1 if area of Polygon 2 = 90 cm2.
4) Assume STUVWX is similar to ABCDEF. XS = 24 cm and UV = 32 cm. FA = 3x + 2 and CD = 9x – 4 a) Find the measures of FA and CD. FA = _________ CD = __________ b) If the area of ABCDEF is 33 cm2, what is the area of STUVWX? Area STUVWX = ______________