A rectangular piece of plywood has a diagonal that measures three feet more than the width. The length of the plywood is three times the width. What is the length of the plywood diagonal?

Respuesta :

Answer:

The length of the plywood diagonal is [tex]4.387\ units[/tex]

Step-by-step explanation:

Let

x-----> the length of the rectangle

y----> the width of the rectangle

we know that

The diagonal of rectangle is equal to

[tex]d=\sqrt{x^{2}+y^{2} }[/tex] -----> equation A

[tex]d=y+3[/tex] ----> equation B

[tex]x=3y[/tex] -----> equation C

substitute equation C and equation B in equation A and solve for y

[tex](y+3)=\sqrt{(3y)^{2}+y^{2}}[/tex]

squared both sides

[tex](y+3)^{2}=10y^{2}\\ \\y^{2}+6y+9=10y^{2}\\ \\9y^{2}-6y-9=0[/tex]

Solve the quadratic equation by graphing

The solution is [tex]y=1.387\ units[/tex]

see the attached figure

Find the value of d

[tex]d=y+3[/tex]----- > [tex]d=1.387+3=4.387\ units[/tex]

Ver imagen calculista