Can someone solve this and explain it in steps to someone that have never learned this?
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Answer:
Step-by-step explanation:
in third quadrant sin is negative.
sin² θ+cos² θ=1
sin²θ+(-16/20)²=1
sin²θ+(-4/5)²=1
sinθ=±√(1-16/25)
=±√((25-16)/25)
=±√(9/25)
=±3/5
so
sin θ=-3/5