Question

25. Using the same units as the given angles, state:
a) principal angle b) related acute angle c) co-related acute angle
d) a positive co-terminal angle d) a negative co-terminal angle
i)
3
17

ii) 172

Answer 1

i)
a) Principal angle: 3
b) Related acute angle: 3
c) Co-related acute angle: 3
d) A positive co-terminal angle: 7π or 11π or 15π or 19π or 23π (any integer multiple of 2π added or subtracted)
e) A negative co-terminal angle: -5π or -9π or -13π or -17π (any integer multiple of -2π added or subtracted)

ii)
a) Principal angle: 172
b) Related acute angle: 172
c) Co-related acute angle: 8
d) A positive co-terminal angle: 188 or 352 or 516 or 680 (any integer multiple of 180 added or subtracted)
e) A negative co-terminal angle: -196 or -360 or -524 or -688 (any integer multiple of -180 added or subtracted)