The N(θ, σ²) (σ known) p.d.f. is of the exponential type.
In fact,
f(x;\theta)={\frac{1}{{\sqrt{2\pi}}\sigma}}e^{-{\frac{(x-\theta)^{2}}{2\sigma^{2}}}}={\frac{1}{{\sqrt{2\pi}}\sigma}}e^{-{\frac{\theta^{2}}{2\sigma^{2}}}}\times e^{{\frac{\theta}{\sigma^{2}}}x}\times e^{-{\frac{x^2}{2\sigma^{2}}}},
and this is of the form(4)
f(x;\theta)=C(\theta)e^{Q(\theta)T(x)}\times h(x),\ \ \ \ x\in\Re,\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ (4)with C(\theta)={\frac{1}{\sqrt{2\pi}\sigma}}e^{-{\frac{\theta^{2}}{2\sigma^{2}}}},\,Q(\theta)={\frac{\theta}{\sigma^{2}}} strictly increasing, T(x)=x,\;\mathrm{and}\;h(x)=e^{-x^{2}/2\sigma^{2}}.