Quadratic equations

Question

a triangle has base 4 m more than it's altitude. is it's area is 70 m^2, find it's altitude

Answer 1

Length of Base (B) = Length of Altitude (A) plus 4m

 

B = A + 4

 

Area = 1/2 [(A+4) * (A)]

 

Area = 1/2 [(A^2 + 4A)]

 

2 (70 m^2) = A^2 + 4A

 

0 = A^2 + 4A - 140 m^2

 

Solve by plugging the factors into the Quadratic Equation, and let me know what you get.