tolong jelaskan cara mengerjakannya

cos(90-@) = OC/OA' = B'A'/OA'
cos(90-@) = sin@

sin(90-@) = A'C/OA' = OB'/OA'
sin(90-@) = cos@

tan(90-@) = (sin(90-@))/(cos(90-@)) = cos@/sin@ = cot@

sec(90-@) = 1/cos(90-@) = 1/sin@ = cosec@

csc(90-@) = 1/sin(90-@) = 1/cos@ = sec@

cot(90-@) = 1/tan(90-@) = 1/cot@ = tan@

Oke