SOLUTION: How to find the area of the shaded region in a triangle if: You know that the triangle is composed of two smaller triangles. And, the first small triangle has the base of 5 and you

Algebra ->  Parallelograms -> SOLUTION: How to find the area of the shaded region in a triangle if: You know that the triangle is composed of two smaller triangles. And, the first small triangle has the base of 5 and you      Log On


   



Question 722681: How to find the area of the shaded region in a triangle if: You know that the triangle is composed of two smaller triangles. And, the first small triangle has the base of 5 and you don't know the height. You just know that the other side of the triangle measures 8. And the second smaller triangle has a base of 4....?
Answer by Edwin McCravy(20059) About Me  (Show Source):
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How to find the area of the shaded region in a triangle if: You know that the triangle is composed of two smaller triangles. And, the first small triangle has the base of 5 and you don't know the height. You just know that the other side of the triangle measures 8. And the second smaller triangle has a base of 4....?
 

Use the Pythagorean theorem on the right triangle on the left to find h:

 c² = a² + b²
 8² = 5² + h²
 64 = 25 + h²
 39 = h²
√39 = h

Now that we have the height, we can find the area.
The whole base of the whole big triangle is 5+4 or 9

A = 1%2F2·b·h

A = 1%2F2·9·√39

A = 28.10249099  [Round to the number of decimal places your
                  teacher asks you to]

Edwin