The width of a rectangle is one-fifth as much as the length. The perimeter is 120 cm. Find the leggth and width.
length = 50cm width = 10cm
how do they do this?
2006-12-11 14:34:42 · 5 answers · asked by grem 3 in Science & Mathematics ➔ Mathematics
I) (Width = 1/5 length
II) (2L + 2w = 120
2L + 2w = 120
2L + 2(1/5L) = 120
12/5L = 120
L = (120 : 12) *5
L = 50cm
w = 1/5 L
w = 1/5*50
w = 10 cm
Answer is: the length, 50cm, and width (10cm).
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2006-12-11 14:40:47 · answer #1 · answered by aeiou 7 · 0⤊ 0⤋
The perimeter is twice (the length + the width), or 2(L + W). So half the perimeter, 60, is L + W. Now the width is 1/5 the length, so the length is 5 times the width. So L = 5W. Therefore 60 = W + 5W = 6W. Divide by 6 to ger W = 10. Then multiply it by 5 to get the length: 50.
2006-12-11 14:38:04 · answer #2 · answered by Amy F 5 · 0⤊ 0⤋
L =5W
P = 2(L+W)
P = 2 (5W + W)
120 = 2 (6W)
6W = 60
W = 60 / 6 = 10cm
L = 5W = 5*10 = 50cm
2006-12-11 14:44:25 · answer #3 · answered by M. Abuhelwa 5 · 0⤊ 0⤋
w=(1/5)l
2w+2l=120
so
w=(1/5)l
w=-l+60 (switch all the signs so that it reads -w=l-60)
(6/5)l-60=0
l=50 (plug this into the w=(1/5)l so that)
w=(1/5)50=10
w=10 cm
l=50 cm
2006-12-11 14:41:03 · answer #4 · answered by Carter 2 · 0⤊ 0⤋
p=120=2w+2l
l=5w
120=2w+10w=12w
w=10
l=5w=50
length=50cm
width=10 cm
2006-12-11 14:40:20 · answer #5 · answered by yupchagee 7 · 0⤊ 0⤋