Yoshi is using a compass to navigate back to base camp. the compass, according to the sporting goods store from which it was purchased, has an area of 12.56 square centimeters. what is the compass's diameter?

Im not sure but it looks like you have a bad compass

Normally, compasses are circles
you didn't give us a height so we only need to compute the area of the face of the compass

area of circle=pir²
2r=d so

area=12.56
12.56=pir³
aprox pi=3.141592
divide both sides by pi or 3.141592
3.99=r³
sqrt both sides
about 2
2=r

2r=d
2(2)=d
4=d

diameter is 4cm