How many isosceles triangles with whole-number length sides have a perimeter of 20 units?
How many isosceles triangles with whole-number length sides have a perimeter of 20 units?
Start with the shortest possible base, then work upwards.
Base Sides
1 9.5 Won't work. The problem says whole-number length sides.
2 9
4 8
6 7
8 6
10 5 Won't work. Triangle Inequality Theorem, which states that
the sum of any two sides is greater than the third side.
Looks like the answer is going to be that there are 4 of them.
.