1. **State the problem:** We are given two similar figures (arrows) with known side lengths and need to find the unknown length $x$ in the larger figure. 2. **Recall the property of similar figures:** Corresponding sides of similar figures are proportional. This means the ratio of one side in the smaller figure to the corresponding side in the larger figure is constant. 3. **Set up the proportion:** From the smaller arrow, the base length is 8 in, and the height is 4 in. From the larger arrow, the height is 10 in, and the base length is $x$ (unknown). The proportion is: $$\frac{4}{10} = \frac{8}{x}$$ 4. **Solve for $x$:** Cross-multiply: $$4 \times x = 10 \times 8$$ $$4x = 80$$ Divide both sides by 4: $$\cancel{4}x = \frac{80}{\cancel{4}}$$ $$x = 20$$ 5. **Answer:** The length of $x$ is $20$ inches.