Icant figure this out i could use some plz

What is the least common multiple for 6 and 8? what is the least common multiple for 4 and 12 ? what is the least common multiple for 11 and 12? what is the least common multiple for 3 and 6?

Answer each of the questions for the following diagram: 1. what type of angles are these? 2. solve for x. what does x equal? 3. what is the measure of the angles?

Cd is the perpendicular bisector of both xy and st, and cy=20. find xy.