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Question
The perimeter of an equilateral triangle is 30 cm. The area is
Options
`10sqrt(3) "cm"^2`
`12sqrt(3) "cm"^2`
`15sqrt(3) "cm"^2`
`25sqrt(3) "cm"^2`
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Solution
`25sqrt(3) "cm"^2`
Explanation;
Hint:
Perimeter of an equilateral triangle = 30 cm
3a = 30 cm
a = `30/3`
= 10 cm
Area of an equilateral triangle = `sqrt(3)/4 "a"^2 "sq.units"`
= `sqrt(3)/4 xx 10 xx 10`
= `25sqrt(3) "cm"^2`
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