The length of a rectangle is five times its width. If the area of the rectangle is 125m^2 , find its perimeter.
2006-11-25 04:44:58 · 8 answers · asked by Ken H 1 in Science & Mathematics ➔ Mathematics
L=5W
Area= LxW
Area=5WxW=5W^2
125=5W^2 so W^2=25 if you extract the square root you get W=5
L=5xW=25
Perimeter=2xL+2xW=50+10=60m
Voila
2006-11-25 04:52:20 · answer #1 · answered by Λиδѓεy™ 6 · 0⤊ 0⤋
A = lw; where A = area of a rectangle of l length and w width.
Given l = 5w; so that A = lw = 5w X w = 5w^2 = 125 m^2. Thus w^2 = 25 m^2; and w = 5 meter and l = 5w = 25 meter.
Perimeter = 2w + 2l = 2X5 + 2X25 = 10 meter + 50 meter = 60 meter.
Lesson learned: when you have two unknowns (l and w), but one is known in terms of the other (l = 5w), we can solve for one of the unknowns first (w = 5) and then use that answer to solve for the second unknown (l = 25).
2006-11-25 04:58:24 · answer #2 · answered by oldprof 7 · 0⤊ 0⤋
here l=5b, given area=lb=125, substitute l=5b so we get 5b.b=125 so 5b^2=125, b^2=25, b=+5 or -5 since the value cant be negative b=+5.now l=5b=5*5=25. we have l=25, b=5 perimeter=l+b+l+b=2(l+b)=2(25+5)=2(30)=60m.
2006-11-25 04:54:49 · answer #3 · answered by arivali 1 · 0⤊ 0⤋
width is 5 length is 25 ...p=2(30)=60
2006-11-25 04:54:20 · answer #4 · answered by chochang_special45571 1 · 0⤊ 0⤋
125=l*w, 125=5w*w, 125=5(w)squared, 125/5=(w)squared, 25=(w)squared, w=5m, 125=l*5, l=125/5, l=25m. P=2*25+2*5, P=60m
2006-11-25 05:11:31 · answer #5 · answered by Deano 7 · 0⤊ 0⤋
w=x
l=5x
A=wl
125=5x^2
x^2=25
x=5
width=5 and the length is 25
P=2w+2l
P=10+50
P=60m
2006-11-25 04:49:30 · answer #6 · answered by 7 · 0⤊ 0⤋
10w+2w=12w is the perimeter
5w^2=125
w^2=25
w=5
l=25
perimeter=60m
2006-11-25 04:53:29 · answer #7 · answered by raj 7 · 0⤊ 0⤋
l=5w
A=125=lw=5w^2
w^2=25
w=5
l=25
2006-11-25 05:04:28 · answer #8 · answered by yupchagee 7 · 0⤊ 0⤋