Respuesta :

Answer:

The length of the base is 11 meters.

Step-by-step explanation:

The diagram of the triangle is not shown; However, the given details are enough to solve this question.

Given

Shape: Triangle

Represent the height with h and the base with b

[tex]b = 3 + 2h[/tex]

[tex]Area = 22[/tex]

Required

Find the length of the base

The area of a triangle is calculated as thus;

[tex]Area = \frac{1}{2} * b * h[/tex]

Substitute 22 for Area and 3 + 2h for b

The formula becomes

[tex]22 = \frac{1}{2} * (3 + 2h) * h[/tex]

Multiply both sides by 2

[tex]2 * 22 = 2 * \frac{1}{2} * (3 + 2h) * h[/tex]

[tex]44 = (3 + 2h) * h[/tex]

Open the bracket

[tex]44 = 3 * h + 2h * h[/tex]

[tex]44 = 3h + 2h^2[/tex]

Subtract 44 from both sides

[tex]44 - 44 = 3h + 2h^2 - 44[/tex]

[tex]0 = 3h + 2h^2 - 44[/tex]

Rearrange

[tex]0 = 2h^2 +3h - 44[/tex]

[tex]2h^2 +3h - 44 = 0[/tex]

At this point, we have a quadratic equation; which is solved as follows:

[tex]2h^2 +3h - 44 = 0[/tex]

[tex]2h^2 + 11h - 8h - 44 = 0[/tex]

[tex]h(2h + 11) - 4(2h + 11) = 0[/tex]

[tex](h - 4)(2h + 11) = 0[/tex]

Split the above

[tex](h - 4) = 0\ or\ (2h + 11) = 0[/tex]

[tex]h - 4 = 0\ or\ 2h + 11 = 0[/tex]

Solve the above linear equations separately

[tex]h - 4 = 0[/tex]

Add 4 to both sides

[tex]h - 4 + 4 = 0 + 4[/tex]

[tex]h = 0 + 4[/tex]

[tex]h = 4[/tex] ---- First value of h

[tex]2h + 11 = 0[/tex]

Subtract 11 from both sides

[tex]2h + 11 - 11 = 0 - 11[/tex]

[tex]2h = 0 - 11[/tex]

[tex]2h = -11[/tex]

Divide both sides by 2

[tex]\frac{2h}{2} = -\frac{11}{2}[/tex]

[tex]h = -\frac{11}{2}[/tex] ------ Second value of h

Since height can be negative, we'll discard [tex]h = -\frac{11}{2}[/tex]

Hence, the usable value of height is [tex]h = 4[/tex]

Recall that [tex]b = 3 + 2h[/tex]

Substitute 4 for h

[tex]b = 3 + 2(4)[/tex]

[tex]b = 3 + 8[/tex]

[tex]b = 11[/tex]

Hence, the length of the base is 11 meters