Use the identity cos^{^2}(θ) + sin^{^2}(θ) = 1 to find sin(θ) when cos(θ) = 0.5

Really lost on this. Is it something to do with the identities cos^{^2}(x) = 1/2 + 1/2 cos(2x) and sin^{^2}(x) = 1/2 - 1/2 cos(2x) ?

Please provide a solution with steps.