Two regular polygons are such that the ratio between their number of s...
Problem: Find the number of sides of two regular polygons given the ratio of their number of sides is 1:2 and the ratio of measures of their interior angles is 3:4.
Solution:
Let the number of sides of the two polygons be n and 2n, respectively.
Ratio of number of sides:
Since the ratio of their number of sides is 1:2, we have:
n:2n = 1:2
Cross-multiplying, we get:
n x 2 = 2n x 1
Simplifying, we get:
n = 2
Therefore, the polygons have 2 sides and 4 sides, respectively.
Ratio of measures of interior angles:
The interior angle of a regular n-gon is given by:
180(n-2)/n
Therefore, the interior angle of the first polygon, with n sides, is:
180(n-2)/n
And the interior angle of the second polygon, with 2n sides, is:
180(2n-2)/(2n)
The ratio of their measures is given to be 3:4. Therefore, we have:
[180(n-2)/n] : [180(2n-2)/(2n)] = 3:4
Cross-multiplying, we get:
[180(n-2)/n] x 4 = [180(2n-2)/(2n)] x 3
Simplifying, we get:
12n - 24 = 6n
Solving for n, we get:
n = 4
Therefore, the first polygon has 4 sides and the second polygon has 8 sides.
Final Answer:
The two regular polygons have 4 sides and 8 sides, respectively.
Two regular polygons are such that the ratio between their number of s...
Let the number of sides of the regular polygon with the fewer number of sides be x, and y be the number of sides of the polygon with the greater number of sides.
xy=12 solving for y: y=2x
The measure of an interior angle of a regular polygon (I) is:
I=(n−2)180n
(x−2)180x(y−2)180y=34
Simplifying:
y(x−2)x(y−2)=34
Substituting for y:
2x(x−2)x(2x−2)=34
Cross multiplying and distributing:
8x2−16x=6x2−6x
Combine like terms:
2x2−10x=0
Factor:
2x(x−5)=0
Therefore, x = 0 or x = 5.
Eliminate x = 0, thus, x = 5 and y = 10, or the number of sides of the two regular polygons are 5 and 10.
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