$$
begin{align*}
m &= 1 \
d &= 4.5 ~ mu text{m} \
theta &= 8.2 text{textdegree}
end{align*}
$$

The wavelength of the light that shines on a diffraction grating through an angle to the first order can be obtain by applying the expression for constructive interference by a diffraction grating :

$$
begin{align*}
d sin theta &= m lambda \
lambda &= dfrac{d sin theta}{m} \
&= dfrac{4.5 cdot 10^{-6} text{ m} (sin 8.2 text{textdegree})}{1}
end{align*}
$$

$$
{boxed{lambda = 641.83 text{ nm}}}
$$

$$
begin{align*}
m &= 1 \
d &= 1.3 cdot 10^{-5} text{ m} \
lambda &= 670 text{ nm}
end{align*}
$$

The angle to the first order of a light on a diffraction grating can be obtain by applying the expression for constructive interference by a diffraction grating :

$$
begin{align*}
d sin theta &= m lambda \
sin theta &= dfrac{m lambda}{d} \
theta &= {sin}^{-1} left( dfrac{m lambda}{d} right) \
&= {sin}^{-1} left( dfrac{1 (670 cdot 10^{-9} text{ m})}{1.3 cdot 10^{-5} text{ m}} right)
end{align*}
$$

$$
{boxed{theta = 2.95 text{textdegree}}}
$$