Circle Segment
1. **Problem Statement:**
A circular clock has radius $r=20$ cm. A chord forms an equilateral triangle with two radii. We need to find the percentage area of the smaller segment created by this chord relative to the total circle area.
2. **Given:**
- Radius $r=20$ cm
- Triangle formed is equilateral, so each angle at center is $60^\circ$
- $\pi=3.14$, $\sqrt{3}=1.732$
3. **Calculate total area of the circle:**
$$\text{Area}_{circle} = \pi r^2 = 3.14 \times 20^2 = 3.14 \times 400 = 1256 \text{ cm}^2$$
4. **Calculate area of the equilateral triangle formed by two radii and the chord:**
- Side length of triangle = radius = 20 cm
- Area of equilateral triangle formula:
$$\text{Area}_{triangle} = \frac{\sqrt{3}}{4} s^2 = \frac{1.732}{4} \times 20^2 = 0.433 \times 400 = 173.2 \text{ cm}^2$$
5. **Calculate area of the sector formed by the $60^\circ$ angle:**
- Sector area formula:
$$\text{Area}_{sector} = \frac{\theta}{360} \times \pi r^2 = \frac{60}{360} \times 1256 = \frac{1}{6} \times 1256 = 209.33 \text{ cm}^2$$
6. **Calculate area of the smaller segment:**
- Segment area = Sector area - Triangle area
$$\text{Area}_{segment} = 209.33 - 173.2 = 36.13 \text{ cm}^2$$
7. **Calculate percentage of the smaller segment area relative to the total circle area:**
$$\text{Percentage} = \frac{36.13}{1256} \times 100 = 2.88\%$$
**Final answer:** The smaller painted segment represents approximately **2.88%** of the clock's total area.