height = base * sqrt(3) / 2
Let me show you why:
An equilateral triangle has all sides the same, and all angles = 60 degrees.
So, if you draw a line from the top of the triangle straight down to the bottom, you'll see that you've divided the triangle in half into two equal, right-angled triangles.
Now, I'm going to skip a little bit of explanation here and ask you to notice that the two triangles are 30-60-90 triangles, which means that the sides of the triangle bear a ratio of 1:2:sqrt(3) where 1 is the base, 2 is the hypotenuse, and sqrt(3) is the line that the two new triangles share.
So, take that ratio between the bottom side of the triangle (this is kind of hard without a picture) and the shared side, and they will have the ratio 1:sqrt(3), or 1/sqrt(3).
Set this equal to the base / 2 (remember that we cut the bottom in half) divided by x:
1/sqrt(3) = (b/2) / x
and solve for x:
x = (b/2)*sqrt(3).
If the explanation doesn't make sense, just use the formula for now. :)
2006-07-13 16:56:55
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answer #1
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answered by Josh 2
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An equilateral triangle has three equal sides and three equal angles. Therefore, each side is of length a and each angle is 60º. If you draw a line from the top angle straight down, you will have a right-triangle, where the length of the line you drew is the height.
Since the hypotenuse of the right triangle is a, and the bottom of the triangle is a/2 (because the line divides the bottom into two equal parts), the height is â(a^2-(a/2)^2)=â(3/4a^2)= â3a/2.
Therefore the height of an equilateral triangle with side length a is â3a/2=sqrt(3)a/2
2006-07-13 23:52:14
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answer #2
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answered by Eulercrosser 4
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An equilateral triangle has 60 degree angles. If you split it in half, you get a 30-60-90 triangle, which is a right triangle. Then you can use a^2+b^2=c^2 to determine the height.
2006-07-13 23:43:33
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answer #3
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answered by djbreslin 2
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1/2*b*h is the equation for a right triangle. If you cut the base in half you get a right triangle. The height is the same.
2006-07-13 23:43:46
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answer #4
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answered by DoctaB01 2
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pythagorean theorum. If you cut the triangle in half, you create a 90 degree angle. The length of one side, and the lenght of half the other side are given. You have to find the third. A^2+B^2=C^2
2006-07-13 23:45:25
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answer #5
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answered by guyfromcroswell 2
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height = Roof 2[side^2 + bottom ^ 2]
2006-07-14 06:46:44
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answer #6
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answered by Christine** 2
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1/2*Base*height = area.
Therefore, height = (area*2)/base
2006-07-14 00:59:37
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answer #7
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answered by K.J. Jeyabaskaran K 3
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Given the side s,
h = sqr(s^2 - (s/2)^2)
h = sqr(s^2 - s^2/4)
h = s x sqr(3)/2
2006-07-14 00:19:47
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answer #8
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answered by ideaquest 7
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let r be the side then take square root of 3/4 &multiply it with r.
2006-07-14 01:02:58
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answer #9
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answered by Anonymous
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a+b=c
2006-07-13 23:43:23
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answer #10
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answered by ebay_convert 5
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