Problem:
Two of the three sides of a triangle are 20 and 15 . Which of the following numbers is not a possible perimeter of the triangle?
Answer Choices:
A.
B.
C.
D.
E.
Solution:
By the Triangle Inequality the third side must be greater than and less than . Therefore the perimeter must be greater than and less than . Among the choices only cannot be the perimeter.
The problems on this page are the property of the MAA's American Mathematics Competitions