math 209
posted by trina .
Area of a sail. The area in square meters for a triangle is given by A(x)=x^2 +5x +6.
a.) Find A(5)
b) if the height of the sail is x+3 meters, then what is the length of the base of the sail when area is x^2 +5x+6m^2?

Surely you can find the area of a triangle given the formula. A(5) means area when x is five.
For the second, Area=1/2 base*height. You know ARea (x^2+5x+6), height is x+3, solve for base in terms of x.