Answer: proof below
<u>Step-by-step explanation:</u>
Use the Difference formula for sin:
sin (A - B) = sin(A)·cos(B) - cos(A)·sin(B)
sin (180° - θ) = sin(180°)·cos(θ) - cos(180°)·sin(θ)
= 0 · cos(θ) - -1 · sin(θ)
= 0 - -sin(θ)
= + sin(θ)
sin (180° - θ) = sin(θ)