Calculate desired angle of robot to hit target

Given a robot pose (x, y, theta), calculate the desired angle the robot needs to be at to hit a blue or red speaker target.

Fill out the following spreadsheet: https://docs.google.com/spreadsheets/d/1GLZCExD-NNWCd-8VFazB9PmoWSFSxYkw2uosHOahNtc/edit#gid=1634972065

x,y should be provided from the odometry estimation, theta should be provided from the pigeon