Combinations
nCr
you have n items and how many ways are there to chose r of them
nCr=

remember than n! means n times all numbers before like
3!=3*2*1, 5!=5*4*3*2*1
9 stations, how many ways are there to chose 6 of them
9C6=

=

=

=

=

=
84
84 ways
What are the other two sides?
Answer:20000
Step-by-step explanation:
30+1000+4000
180°. :)
All angles in a triangle sum to 180° proof.