SOLUTION: have an equilateral triangle with sides of 13 in. How do I find the area? I know formula is A=1/2bh. Base is 13 but what is height?

Question 562459: have an equilateral triangle with sides of 13 in. How do I find the area? I know formula is A=1/2bh. Base is 13 but what is height?
Answer by Edwin McCravy(20060) (Show Source): You can put this solution on YOUR website!
have an equilateral triangle with sides of 13 in. How do I find the area? I know formula is A=1/2bh. Base is 13 but what is height?

Draw it:



Draw the height (in green), which will divide the bottom
13 in. bottom side into two 6.5 in. parts:




If we look at only the left half of the triangle, we
see that it is a right triangle:



The Pythagorean theorem applies to right triangles
and says that

 6.5� + h� = 13�
42.25 + h� = 169  
        h� = 126.75
         h = 
         h = 11.25833025     

Now use the formula:

   A = bh
   A = (6.5)(11.24833025)
   A = 36.58957331 square inches

Edwin

RELATED QUESTIONS
An equilateral triangle has an area of 300square root of 3. Find the apothem. My... (answered by Earlsdon)

Please help me solve this: Find the formula for the area of an isosceles right triangle... (answered by Earlsdon)

How do You find the area of an equilateral triangle with a radius of 2 radical 3? All I... (answered by drk)

How do You find the area of an equilateral triangle with a radius of 2 radical 3? All I... (answered by richwmiller,stanbon)

I am working on a summer math project and it deals with the pythagorean theorem, which is (answered by Fombitz)

Thanks in advance to whoever helps me. The question is, The area of an equilateral... (answered by Alan3354)

Find the perimeter of an equilateral triangle whose area is equal to that of a triangle... (answered by math_tutor2020)

An isosceles triangle has a base of 10 and legs of 13. Another isosceles triangle has... (answered by KMST)

How do I do this? Find the altitude of the triangle. The shape is a triangle with... (answered by checkley75)