1. **State the problem:**
We are given a triangle with angles $A=40^\circ$, $B=45^\circ$, and side $c=28$ ft opposite angle $C$. We need to find angle $C$, side $a$ opposite angle $A$, and side $b$ opposite angle $B$ using the Law of Sines.
2. **Find angle $C$:**
The sum of angles in a triangle is $180^\circ$.
$$C = 180^\circ - A - B = 180^\circ - 40^\circ - 45^\circ = 95^\circ$$
3. **Law of Sines formula:**
$$\frac{a}{\sin A} = \frac{b}{\sin B} = \frac{c}{\sin C}$$
4. **Calculate side $a$:**
$$a = c \times \frac{\sin A}{\sin C} = 28 \times \frac{\sin 40^\circ}{\sin 95^\circ}$$
Calculate intermediate values:
$$\sin 40^\circ \approx 0.6428, \quad \sin 95^\circ \approx 0.9962$$
$$a = 28 \times \frac{0.6428}{0.9962} = 28 \times 0.6453 = 18.049$$
5. **Calculate side $b$:**
$$b = c \times \frac{\sin B}{\sin C} = 28 \times \frac{\sin 45^\circ}{\sin 95^\circ}$$
Calculate intermediate values:
$$\sin 45^\circ \approx 0.7071$$
$$b = 28 \times \frac{0.7071}{0.9962} = 28 \times 0.7097 = 19.871$$
6. **Final answers rounded to three decimal places:**
$$C = 95^\circ$$
$$a = 18.049 \text{ ft}$$
$$b = 19.871 \text{ ft}$$
Law Of Sines 6Ab09F
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