The area of the triangle is 35 square feet. Use a quadratic equation to find the length of the base. Round your answer to the nearest tenth.

10.6 ft

Step-by-step explanation:

The complete question is:

The area of the triangle is 35 square feet. Use a quadratic equation to find the length of the base. Round your answer to the nearest tenth.Base=x+4 Height=x

SOLUTION:

As you know, Area of triangle 'A' = 1/2 x b x h

Where,

Base 'b' = x+4

Area 'A' = 35 ft²

Height 'h'= x

35 = (1/2)(x+4)x

35 =(x² + 4x)/2

2 * 35 =x² + 4x

70 = x² + 4x

x² + 4x - 70=0

Formula for the quadratic equation is

x = [- b ± √(b² - 4ac)]/2a

Where,

a=1,  b= 4,   c=-70

Plugging in the values.

x = [- 4 ± √4² - (4 × 1 × - 70)] / (2 × 1 )

x = [- 4 ± √(16  + 280)]/2

x = [- 4 ± √296]/2

x = (- 4 + 17.2)/2 or x = (- 4 - 17.2)/2

x = 13.2/2 or x = - 21.2/2

As, we choose to ignore negative value of 'x'

Therefore, x = 13.2/2 = 6.6

And, Length of the base will be:

x + 4 = 6.6 + 4 => 10.6 ft