1. **Problem Statement:** Find the area of a semicircle with diameter divided into three parts A, B, and C such that $A+B+C=7$ units. 2. **Understanding the problem:** The total diameter of the semicircle is $7$ units. 3. **Formula for area of a semicircle:** The area $A_{semi}$ of a semicircle with radius $r$ is given by: $$A_{semi} = \frac{1}{2} \pi r^2$$ 4. **Calculate the radius:** Since the diameter $d = 7$, the radius $r$ is: $$r = \frac{d}{2} = \frac{7}{2} = 3.5$$ 5. **Calculate the area:** Substitute $r=3.5$ into the area formula: $$A_{semi} = \frac{1}{2} \pi (3.5)^2 = \frac{1}{2} \pi \times 12.25 = 6.125 \pi$$ 6. **Final answer:** The area of the semicircle is: $$\boxed{6.125 \pi \text{ square units}}$$ This is approximately $6.125 \times 3.1416 = 19.24$ square units.