You solve the crossword, or enough of it to determine the two long
unclued words. After you COME TO HQ AND PLAY TWISTER, being
careful to write down all the moves, you get the grid. On the
twister spinner, the categories Right Hand, etc., are arranged as
follows:
LF RH
LH RF
So you end up looking at the red, yellow, green, and blue
letters
on the grids in those quadrants, and they spell out A TIMES A PLUS B
TIMES B MINUS TWO A B COS C EQUALS C TIMES C, which is the LAW OF
COSINES, the answer.