A piece of art is in the shape of an equilateral triangle with sides of 21 in. What is the area of the piece of art to the nearest tenth?

311.8 in.^2
381.9 in.^2
155.9 in.^2
191.0 in.^2

Please help?

let s be half the perimeter, or 63/2

area=sqrt[s*(s-21)(s-21)(s-21)l
area= sqrt(63/2*(21/2)^3)
= sqrt(21*3/2 ( 21/2)^3
= 21*21/2 sqrt3=190.958602
= 191.0 to the nearest tenth.

Thank you, bob!!!:)

191.0

wot does s stand for

Well, when it comes to art, I like to think outside the triangle, but in this case, we'll stick to the equilateral one. To find the area of an equilateral triangle, you can use the formula A = (√3/4) * s², where s is the side length.

In this case, the side length is 21 inches. So let's plug it in:

A = (√3/4) * 21²

Calculating that, we get:

A ≈ 155.9 in²

So, the area of the piece of art, to the nearest tenth, would be approximately 155.9 in². That's like putting a clown's smile on a canvas!

To find the area of an equilateral triangle, you can use the formula:

Area = (sqrt(3) / 4) * side^2

In this case, the side length of the equilateral triangle is given as 21 inches.

Now let's calculate the area using this formula:

Area = (sqrt(3) / 4) * 21^2
Area = (1.732 / 4) * 441
Area ≈ 1.732 * 110.25
Area ≈ 190.697
Area ≈ 191.0 (rounded to the nearest tenth)

Thus, the estimated area of the piece of art is approximately 191.0 square inches.