The area of triangle is 40. If its height is 2 units more than its bas

The area of a triangle equals to (1/2)*height(h)*the corresponding base(b)
S = (1/2)*h*b =40
h= b + 2
---->(1/2)*(b + 2)*b =40
---->b^2 +2b - 80 =0
We assume that each option is a base of the triangle, so plug in each option by starting from the mid value
b=8--->64 +16 =80--->The answer is B.
We luckily answer the question from the 1st attempt; however, it is recommended to start from the mid value to determine which direction we should choose to check.
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If the mid value results in:
+Greater value, so we know that we need to move upward. Ex: if our mid value is 9, we have 81 + 18 > 80, so we have to move upward.
+Less value, so we know that we need to move downward. Ex: if our mid value is 7, we have 49 + 14<80, so we have to move downward.

We can let n = the length of the base and create the equation:

40 = n(n + 2) * 1/2

80 = n^2 + 2n

n^2 + 2n - 80 = 0

(n + 10)(n - 8) = 0

n = -10 or n = 8

Since n can’t be negative, n must be 8.

Answer: C