Sec. 6

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Sec. 62Similar Polygons
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Figures that are similar () have the same shape
but not necessarily the same size. Angles are
congruent, Sides are proportional
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If two figures are similar, not only are their
sides proportional, all their linear parts are
proportional (such as the height, median,
midsegment, diagonals, etc).
Scale Factor If two polygons are similar, then
the ratio of the lengths of two corresponding
sides is called the scale factor.
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1. The two triangles are similar, find the
missing angles
50
120
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2. Triangle ABC Triangle DEF, find x and y.
D
3
F
A
18
y
C
2
10
x
E
B
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• Two similar rectangles have sides in the
• ratio of 3 7. If the smaller rectangle has
  a perimeter of 50m, find the perimeter of the
  larger rectangle.

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4. Are these polygons similar (the sum of the
angles in a pentagon is 540?)?
5.5
130?
4.6
2.4
130?
1.9
110?
100?
110?
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2.9
5
100?
3.1
100?
100?
2.9
3.1
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Determine whether the polygons are similar. If
so, write the similarity ratio and a similarity
statement and find the scale factor from quad
ABCD to quad EFGH.