Aprism has a surface area of 50 mm2. which sentence describes the effect of measuring the surface area in square centimeters?

Ok, so one way is, like this
divide it by 100 and change to square cm

the way to see why this works is like this

first, 1mm=1/10cm
so if the prism was flattened and cut and moved into a rectangle
let's say legnth was 10mm andn width was 5mm
convert each to cm
legnth is 1cm and width is 0.5
0.5cm^2 is the area

It would be 18 cm