Geometry Math Problem: Find the area of a six-pointed star that is inscribed inside a regular hexagon
The figure shows a star that is inscribed inside a regular hexagon. If the sides of the regular hexagon are 10 cm then find the area of the six-pointed star
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Solution
Previously we discussed the area of the five-point star. Here we can solve the problem with the use of symmetry
We can divide the star into 12 equal triangles also all triangles are equilateral triangles
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From figure
Area of star = 12 × areas of Triangles
Side of triangle = AC/3
∠ABC = 120°
To find AC apply the cosine rule in ∆ABC
AC² = AB² + BC² – 2×AB×BC×cos 120
⇒ AC² = 100 + 100 – 2×10×10× (-½)
⇒ AC² = 300
Thus, AC = 10√3
So side of triangle = 10√3 /3
⇒ Sides of the triangle = 10/√3
Area of triangle = √3 × (10/√3)²/4
⇒ Area of the triangle = 25/√3 cm²
Then the area of star = 12 × 25/√3
⇒ Area of star = 100√3 cm²