20°35′27″*4；100°-36°18′52″；16°23′35″÷5；80°32′15″+90°27′45″；在

20°35′27″*4
=80°140'108''
=82°21'48''
100°-36°18′52″
=63°41'8''
16°23′35″÷5
=3°16'43''
80°32′15″+90°27′45″
=170°59'60''
=171°