Math 213
Sections 9.1, 9.2, & 9.3
Form yourselves into groups of four to answer the following questions. Turn in one copy for
each group with all the group member’s names on it. This worksheet is due Tuesday 8/18
by 4:30 pm in my box.
1. Use a geometric model to find the number of handshakes that take place at a (small)
party of 4 people if each person shakes hands with every one else. Hint: think about
people as points and handshakes as lines.
2. Repeat exercise 1 with 5 people.
3. Repeat the exercise with 25 people.
4. Generalize the exercises above to a party with npeople. Give full and clear justification
for your formula.
1
