SOLUTION: What are the possible triangles with whole number sides and a perimeter of 18 units?

Algebra ->  Triangles -> SOLUTION: What are the possible triangles with whole number sides and a perimeter of 18 units?      Log On


   



Question 595787: What are the possible triangles with whole number sides and a perimeter of 18 units?
Answer by Edwin McCravy(20065) About Me  (Show Source):
You can put this solution on YOUR website!
The maximum side can be no less than 6 when all three sides
are equal in length.

1. When the maximum side is 6, all three sides are 6.

That's 1 way.

2. When the maximum side is 7, the other two sides must have
   sum 11, and be 7 or less, so there are 2 possibilities for
   the other two sides, either 4 and 7 or 5 and 6.

That's 2 more ways.

3. When the maximum side is 8, the other two sides must have
   sum 10, and be 8 or less, so there are 4 possibilities for
   the other two sides, 2 and 8, 3 and 7, 4 and 6, or 5 and 5.

That's 4 more ways.

Total: 1+2+4 = 7 ways.

Edwin