Which of the following is the correct fact about angles at a point?
Angles at a point add up to $360^\circ$360°.
Angles at a point add up to $90^\circ$90°.
Angles at a point add up to $180^\circ$180°.
Investigate with and without digital technologies, angles on a straight line, angles at a point and vertically opposite angles. Use results to find unknown angles.