How many isosceles triangles with whole-number length sides have a perimeter of 20 units? Thanks for the help!
Let x be one of the equal sides and y be the remaining side
We have this system
2x > y
2x + y = 20
Look at the graph : https://www.desmos.com/calculator/rmoylu7ibl
It shows that there are 4 such triangles
6, 6, 8
7, 7, 6
8, 8, 4
9, 9, 2
Thanks CPhill!
+152 
