THIS MONTH'S QUIZ
The three sides of a triangle have lengths a cm, b cm and c cm respectively. We shall call a triangle friendly if each of a, b and c is a whole number not exceeding 20.
1. How many distinct friendly triangles have perimeters of 20 cm ?
(Note: Two triangles with sides 9, 7, 4 and 9, 4, 7, for example, are not considered to be distinct.)
2. How many distinct friendly triangles are right-angled?
3. How many distinct friendly triangles are there altogether?