A.L=π(D×b/2) B.L=π(D-b/2) C.L=π(D+b/2) D.L=π+(D+b/2)
A.L=π+D+b/2 B.L=π-(D+b/2) C.L=π(D+b/2) D.L=π/(D+b/2)
A.L=π(D+h) B.L=π(D-h) C.L=π×D×h D.L=π/(D-h)