How do i determine the exact values of this question

Question

If cos(θ) = -4/5, find ALL the exact values of the other 2 primary trig ratios (sin and tan) and all possible

approximate values of θ (to the nearest degree), when 0^o≤ θ ≤ 360^o

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Answer 1

Arccos (-4/5) = 143^° and 217^°

If cos(θ) = -4/5, then sin(θ) = 3/5 and tan(θ) = -3/4

Answer 2

sin² θ + cos² θ = 1

tan θ = sin θ / cos θ