SOLUTION: An Isosceles Triangle Has Sides 12,12 and 20. What is the altitude of the base? What does this mean and how to solve it?

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Question 964482: An Isosceles Triangle Has Sides 12,12 and 20. What is the altitude of the base? What does this mean and how to solve it?
Answer by addingup(3677) About Me  (Show Source):
You can put this solution on YOUR website!
The base is at the bottom, that's what base means. The triangle goes over the base, so the base does not have altitude. Did you mean the height of the triangle? or is it something else? please re-post and clarify what you need.\
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The unequal side of an isosceles is the base, in your case the base is 20 and the sides 12. To find the height you would use Pythagoras. Draw a line down from the vertex to the middle of the base. Now you have two right angle triangles with known sides:
hypotenuse: 12
short side: 20/2= 10
the missing side is the square root of the square of the hypotenuse minus the square of the known side.
sqrt(144-100)= missing side (equal to height of triangle)
sqrt 44= height of triangle (missing side)
6.63= height of triangle
See illustration: