P = π ⋅ ( R a + R b ) {\displaystyle P=\pi \cdot (R_{a}+R_{b})}
??? R a {\displaystyle \ R_{a}} ??? R b {\displaystyle \ R_{b}} ??? ??????????????? ????? ??
P = 4 a {\displaystyle \ P=4a} ??? a {\displaystyle \ a} ????????????????
P = 2 ⋅ ( L + l ) {\displaystyle P=2\cdot (L+l)}
??? L {\displaystyle \ L} ???????????? ??? l {\displaystyle \ l} ????????????????????????
P = n a {\displaystyle \ P=na}
P = 2 n b sin ( π n ) {\displaystyle P=2nb\sin({\frac {\pi }{n}})}