式15: "A" Subscript, 2 , Baseline equals "R" sine left parenthesis, negative 90 minus StartFraction, "A" Subscript, "O" "B" , Baseline Over 2 , EndFraction , right parenthesisA2=Rsin−90−AOB2
式21: left parenthesis, "P" Subscript, 1 , Baseline plus "R" cos "t" , "P" Subscript, 2 , Baseline plus "R" sin "t" , right parenthesisP1+Rcost,P2+Rsint
21
式22: left parenthesis, "O" Subscript, 1 , Baseline , "O" Subscript, 2 , Baseline , right parenthesis , left parenthesis, "A" Subscript, 1 , Baseline , "A" Subscript, 2 , Baseline , right parenthesisO1,O2,A1,A2
22
式23: left parenthesis, "O" Subscript, 1 , Baseline , "O" Subscript, 2 , Baseline , right parenthesis , left parenthesis, "B" Subscript, 1 , Baseline , "B" Subscript, 2 , Baseline , right parenthesisO1,O2,B1,B2
23
式24: left parenthesis, "R" cos "t" , "R" sin "t" , right parenthesisRcost,Rsint
24
式25: left parenthesis, "P" Subscript, 1 , Baseline plus "R" cos "t" , "P" Subscript, 2 , Baseline plus "R" sin "t" , right parenthesisP1+Rcost,P2+Rsint
25
式26: left parenthesis, "R" cos "t" , "R" sin "t" , right parenthesisRcost,Rsint
26
式27: polygon left parenthesis, "A" , "B" , right parenthesispolygonA,B
27
式28: left parenthesis, "M" Subscript, 1 , Baseline , "M" Subscript, 2 , Baseline plus "h" "t" , right parenthesisM1,M2+ht
