Let's start by assigning meanings to variables:
x = shortest side
2x -3 = longest side
For the third side, we need to solve "longest side is 7 cm less than sum of other two sides":
longest side = third side + shortest side - 7
(2x - 3) = third side + (x) - 7
third side = 2x - x - 3 + 7
third side = x + 4
Perimeter = side 1 + side 2 + side 3
54 = (x) + (2x - 3) + (x + 4)
54 = 4x + 1
4x = 53
x = 53/4 = 13.25
Therefore, substitute x back into our definitions above and you get:
Shortest side = x = 13.25 cm
Longest side = 2x - 3 = 23.5 cm
Third side = x + 4 = 17.25 cm
Check your answer:
Does 13.25 + 23.5 + 17.25 = 54? Yes! therefore, correct!
2006-12-02 06:29:33
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answer #1
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answered by sep_n 3
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find the three equation
a is the longest side , c the shortest
eq 1 a+b+c =54 comes from perimeter is sum of the sides
eq 2 a+7 = b+c
eq 3 a+3 =2c
if you replace b+c by a+7 in 1
you find 2a+7 = 54 a= 23.5
eq 3 26.5 = 2c c = 13.25
and b = 14.75 with any of equation
2006-12-02 14:33:53
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answer #2
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answered by maussy 7
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let say the three sides are of length a cm, b, and c cm
so a+b+c = 54 -- (i)
a be the longest side
(b+c)=7+a --- (ii)
c be the shortest side
2c=3+a -- (iii)
using (i) and (ii)
a+a+7=54
2a=54-7
a=23.5
from (iii)
2c=3+a
put the a value here
c= 12.75
and solve b in (ii)
b=7+a-2
b= 17.75
so three sides = 17.75, 12.75,23.5
and add them to make sure they equal to the perimeter.. \
yes, they do!
2006-12-02 14:24:35
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answer #3
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answered by no man 2
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let the lengths of the 3 sides be L, M and S cm
L + M + S = 54 ................... (1)
L = M + S - 7 â L - M - S = -7 ................ (2a)
and M = L + 7 - S ................. (2b)
L + 3 = 2S â S = ½(L + 3) ......................... (3)
Equation (1) + equation (2a)
2L = 47
L = 23.5
From equation (3) S = 13.25
From equation (2b) M = 30.5 - 13.25 = 17.25
Check 23.5 + 17.25 + 13.25 = 54 YESSSSSSSSS!!!!!!!!!!!
So the lengths of the sides of the triangle are 23.5 cm, 17.25 cm and 13.25 cm
2006-12-02 14:31:15
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answer #4
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answered by Wal C 6
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That's easy :)
Can't you do your own homework ?
2006-12-02 14:22:21
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answer #5
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answered by ? 5
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23.50
13.25
17.25
2006-12-02 14:47:05
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answer #6
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answered by Harry 1
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a+b+c=54
c=a+b-7
2a=c+3
c=2a-3
a+b+2a-3=54
b=c-a+7
b=2a-3-a+7
b=a+4
a+a+4+2a-3=54
4a=53
a=13.25
c=2a-3=23.5
b=a+4=17.25
a+b+c=13.25+17.25+23.5=54
c=13.25+17.25-7=23.5
2a=23.5+3=26.5
a=13.25
2006-12-02 14:33:19
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answer #7
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answered by yupchagee 7
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