Answer:
Radius is the distance from the center of the circle to the edge (if you were to cut just a slice of pizza)
diameter is directly in the middle from one end to the other (if you were to cut the pizza in half)
this means that the diameter is DOUBLE the radius
circumference is the length of the outside of the circle (so the length of the pizza crust)
this one is tricky because to find circumference you need to do (r is the value of the radius)
so for problem 1 the radius is 3 cm (the line is equivalent to if you were trying to cut out one slice of pizza)
the diameter is DOUBLE the radius, so if you were to cut the pizza in half all the way it would be 6 cm
and the circumference () is 2 * pi * 3 cm
because it says to round pi to 3.14, the circumference would be 18.84
lmk if this wasn't a good explanation or if you want help on the other problems too