What is the area of an equilateral triangle with an apothem 2cm long and a side 6.9 cm long?

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Answer 1 · 2015-12-14T23:43:07

#20.7 "cm"^2#

Because your triangle is equilateral, we can use the formula for the area of an regular polygon:

#A = 1/2aP#

where #a# is the apothem and #P# is the perimeter.

The number of sides in a triangle is 3, so #P = 3 * 6.9 "cm" = 20.7 "cm"#.

We've already been given #a#, so now we can plug in our values:

#A = 1/2aP = 1/2(2)(20.7) = 20.7 "cm"^2#