Consider a rectangle whose length, L, is 4 more than twice its width, w. a. Write an expression for L in terms of w. b. Show that the perimeter, P, is equal to = 6 + 8. c. Given the perimeter is 20, find the length and width of the rectangle using your answer to part b.

Mathematics · High School · Thu Feb 04 2021

Answered on

According to the question, Consider length=L and width=W

given that: length is 4 more than twice its width

1.Write an expression for L in terms of w

so, L=2W+4 

2.Show that the perimeter, P, is equal to = 6w + 8

perimeter, P = 2(L+W)

                       =2(2W+4+W)    (* L=2W+4)

                      =2(3W+4)

                    P =6W+8

hence prove that P =6W+8

3. if perimeter is 20, find the length and width of the rectangle

P=2(L+W) above we find the perimeter, we can apply this here:-

20=6W+8

20-8=6W

12=6W

W=12/6

W=2

width is 2 put this value in equation L=2W+4

L(length)=2*2+4

                =4+4

                =8

so length = 8 and width= 2