SOLUTION: The base of a triangle is 3 less than the height. The area of the triangle is 20. Find the base of the triangle

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Question 426491: The base of a triangle is 3 less than the height. The area of the triangle is 20. Find
the base of the triangle
Answer by Gogonati(855) About Me  (Show Source):
You can put this solution on YOUR website!
Solution:Denote x the height of triangle. We know that the area of triangle is:
A=%28b%2Ah%29%2F2 Solve this literal equation with respect to b :
2%2AA=b%2Ah
b=%282%2AA%29%2Fh. Substitute A=20 and h=x and we have:
+b=%282%2A20%29%2Fx Now we write the equation:
x-%282%2A20%29%2Fx=3 Solve this equation:
x%5E2-3x-40=0 There are two roots {-13,5}.
We reject the root -13 because the dimensions are always positive integers.
Answer: The base of triangle is 5 (units: m, cm, feet)