What is the diameter, radius, r2, and circumference?
3 cm

see below

Step-by-step explanation:

given:  

radius of a circle = 3cm

find:

1. diameter

2. radius

3. r²

1) diameter = twice the radius = 2 r = 2 (3) = 6 cm

2) radius = 3 cm

3) r² = 3² = 9 cm

The student should have divided the discounted amount by the percent. The percent should have been written as a decimal.

Step-by-step explanation:

that is what it says in the simple reponse