1. **State the problem:** We have a right triangle with angle $A = 43^\circ$, side $AC = 650$ yards adjacent to angle $A$, and we want to find side $AB = a$, which is opposite angle $A$. 2. **Formula used:** In a right triangle, the tangent of an angle is the ratio of the opposite side to the adjacent side: $$\tan(A) = \frac{\text{opposite}}{\text{adjacent}} = \frac{a}{650}$$ 3. **Solve for $a$:** $$a = 650 \times \tan(43^\circ)$$ 4. **Calculate $\tan(43^\circ)$:** Using a calculator, $$\tan(43^\circ) \approx 0.9325$$ 5. **Find $a$:** $$a = 650 \times 0.9325 = 605.125$$ 6. **Round to the nearest whole number:** $$a \approx 605$$ yards **Final answer:** $a = 605$ yards.