Home > Math Group > Question and Answer

Math Group

Question:

tina321
tina321
Student
High School - 12th Grade

The area of my rectangle is 173.4in (squared), the ratio of width and length is 3/5, what is the length and width of the rectangle?

Rate question:

Posted by tina321 on Thursday March 12, 2009 at 5:53 PM and tagged with area, length, math, ratio, rectangle, squared, width.

Answers:

  1. giorgiana1976
    giorgiana1976 Teacher
    Doctorate

    eNotes Editor

    We know that the formula for the area of a rectangle is:

    A=lxL

    Also we know from the hypothesis that the ratio between length and width is:

    l/L=3/5 =>5*l = 3*L => l = (3/5)*L

    A = 173.4 inch squared

    In the formula of area, we'll substitute the width l = (3/5)*L

    A = (3/5)*L*L

    173.4 = (3/5)*L^2

    (5*173.4)/3 = L^2

    867/3 = L^2

    289 = L^2

    17*17=289

    17*17 = L*L

    L=17inch

    l = (3/5)*L

    l = (3/5)*17

    l = 51/5

    l= 10.2 inch

    Rate answer:

    Posted by giorgiana1976 on Friday March 13, 2009 at 3:30 AM

  2. neela
    neela Teacher
    Graduate School

    eNotes Editor

    We assume the rectangle with sides measuring l and b, and find them by establing equations with the given conditins.

    l*b=173.4 isquare inch.=>

    b =173.4/l----------(1)

    b/l=3/5 =0.6=>

    b=0.6l--------------(2)

    Since in (1) and (2) left sides  are equal , right sides  should be equal:

    0.6l=173.4/l=>

    0.6l^2=173.4=>

    l^2=173.4/0.6=289=> l=sqrt(289)=17 inch

    Substituting the value of l=17 in (1), we get

    b =173.4/17=10.2in.

    Therefore, length =17cm and width =10.2cm

     

    Rate answer:

    Posted by neela on Friday June 5, 2009 at 6:50 AM