SOLUTION: The longest side of the triangle is thrice the length of the shortest side.The medium-sized side is 4cm less than the longest side.The perimeter of the triangle is 31cm.how long is

Algebra ->  Pythagorean-theorem -> SOLUTION: The longest side of the triangle is thrice the length of the shortest side.The medium-sized side is 4cm less than the longest side.The perimeter of the triangle is 31cm.how long is      Log On


   



Question 1062653: The longest side of the triangle is thrice the length of the shortest side.The medium-sized side is 4cm less than the longest side.The perimeter of the triangle is 31cm.how long is the longest side?
Found 2 solutions by Theo, MathTherapy:
Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
let a = smallest side.
let b = medium side
let c = largest side.

a + b + c = 31

c = 3a
b = c - 4 = 3a - 4

a+ b + c = 31 becomes:

a + (3a - 4) + 3a = 31

simplify and combine like terms to get:

7a - 4 = 31

add 4 to both sides to get:

7a = 35

solve for a to get a = 5

you get:

a = 5
c = 15
b = 11

a + b + c = 31

solution is:

largest side is 15 cm.


Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!

The longest side of the triangle is thrice the length of the shortest side.The medium-sized side is 4cm less than the longest side.The perimeter of the triangle is 31cm.how long is the longest side?
Let longest side be L
Then shortest side = L%2F3
Middle side = L - 4
We then get: L+%2B+L%2F3+%2B+L+-+4+=+31 =====> 2L+%2B+L%2F3+=+35
6L + L = 105 ------ Multiplying by LCD, 3
7L = 105
L, or longest side = highlight_green%28matrix%281%2C4%2C+105%2F7%2C+or%2C+15%2C+cm%29%29