Deem_Skills
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how did they get from the first step to the second? why are they squaring?
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math question (1 Viewer)
- Thread starter Deem_Skills
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how did they get from the first step to the second? why are they squaring?
It seems to come from formula for the area of a pentagon. After simplification you end up with the squares. Google "area of pentagon" on google and you will understand.
Easy.
Area of smaller pentagon : area of larger pentagon = 4:25 =
.: side length of smaller pentagon : side length of larger pentagon = 2 : 5 [the regular pentagons being similar figures]
.: side length of smaller pentagon = (2/5)*22.5 cm = 9 cm
Note: the principle being simply: if A and B are similar figures, with length of one side of A being "a"
and the length of the corresponding side of B being 'b', then
area of A : area of B = square of 'a' : square of 'b'.
Area of smaller pentagon : area of larger pentagon = 4:25 =
.: side length of smaller pentagon : side length of larger pentagon = 2 : 5 [the regular pentagons being similar figures]
.: side length of smaller pentagon = (2/5)*22.5 cm = 9 cm
Note: the principle being simply: if A and B are similar figures, with length of one side of A being "a"
and the length of the corresponding side of B being 'b', then
area of A : area of B = square of 'a' : square of 'b'.
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