Question

Raza unui cerc cu lungimea de 180$\pi$(pi) dam este ega cu ......... Dm

Answer 1

 $L_{cerc}=2\pi{R}=180\pi\;dm\;;\;\;R=180\pi : (2\pi)=90\,dm$
 Am revenit , conform corecturii transmise !

Answer 2

lungimea cerc=2pixR
2piR=180pi dm
2R=180dm
R=180:2
R=90dm