Due tomorrow i need on 15,16,17,18,19,20

What is the relationship between all triangles that can be drawn given the same three angles

You dug a hole that was 8 feet deep. after taking a short break, you dug down 3 more feet in the same hole. when finished digging, a tractor accidentally filled the hole with 4 feet of dirt. how deep is your hole now?

How many zeroes do we write when we write all the integers 1 to 243 in base 3?