Respuesta :
Let b be the base of the traingle
Let h be the height of the triangle
The height of a triangle is 3 feet less than the base:
[tex]h=b-3[/tex]The area of the triangle is 230 square feet.
The area of a triangle is:
[tex]A=\frac{1}{2}(b\cdot h)[/tex]For the given triangle:
[tex]\begin{gathered} A=\frac{1}{2}(b\cdot(b-3)) \\ \\ 230=\frac{1}{2}(b\cdot(b-3)) \end{gathered}[/tex]Solve b in the equation above:
[tex]\begin{gathered} 230=\frac{b^2-3b}{2} \\ \\ 2\cdot230=b^2-3b \\ \\ 460=b^2-3b \\ \\ b^2-3b-460=0 \end{gathered}[/tex]Use the quadratic formula:
[tex]\begin{gathered} ax^2+bx+c=0 \\ \\ x=\frac{-b\pm\sqrt[]{b^2-4ac}}{2a} \\ \\ \end{gathered}[/tex][tex]\begin{gathered} b=\frac{-(-3)\pm\sqrt[]{(-3)^2-4(1)(-460)}}{2(1)} \\ \\ b=\frac{3\pm\sqrt[]{9+1840}}{2} \\ \\ b=\frac{3\pm\sqrt[]{1849}}{2} \\ \\ b=\frac{3\pm43}{2} \\ \\ b_1=\frac{3+43}{2}=\frac{46}{2}=23 \\ \\ b_2=\frac{3-43}{2}=-\frac{40}{2}=-20 \end{gathered}[/tex]As the length of the base cannot be a negative quantity you use the solution 1.
The base of the triangle is 23ft
Use the value of b to find the heigth:
[tex]\begin{gathered} h=b-3 \\ h=23-3 \\ h=20 \end{gathered}[/tex]Then, the given triangle has the next dimensions:base: 23ftheight: 20ft