Question: 29. The figure below shows a circle, centre $O$, enclosed in a square and 2 quarter circles. Find the total area of the shaded parts.
(Take $\pi = \frac{22}{7}$)
14 cm
Ans: ____________________ cm²
1. **Problem Statement:** We have a square of side length $14$ cm containing a circle centered at $O$ touching all four sides, and two quarter circles drawn from the lower left and lower right corners. We need to find the total area of the shaded parts.
2. **Identify the shapes and their dimensions:**
- Square side length $= 14$ cm.
- Circle inside the square touches all sides, so its diameter $= 14$ cm, radius $r = \frac{14}{2} = 7$ cm.
- Two quarter circles each have radius $= 7$ cm (since they are drawn from corners to bottom center).
3. **Calculate areas:**
- Area of square: $$14 \times 14 = 196 \text{ cm}^2$$
- Area of circle: $$\pi r^2 = \frac{22}{7} \times 7^2 = \frac{22}{7} \times 49 = 154 \text{ cm}^2$$
- Area of one quarter circle: $$\frac{1}{4} \pi r^2 = \frac{1}{4} \times 154 = 38.5 \text{ cm}^2$$
- Area of two quarter circles: $$2 \times 38.5 = 77 \text{ cm}^2$$
4. **Analyze shaded area:**
- The shaded area is the area of the circle plus the two quarter circles minus the overlapping white leaf-shaped regions formed by the quarter circles inside the square.
- The two quarter circles overlap inside the circle, creating two white leaf-shaped regions.
- The total shaded area is the area of the circle plus the two quarter circles minus the overlapping white regions.
5. **Calculate the overlapping white leaf-shaped regions:**
- The two quarter circles together form a semicircle of radius $7$ cm at the bottom.
- The circle inside the square is also of radius $7$ cm.
- The overlapping white region is the area of the semicircle formed by the two quarter circles minus the area of the bottom semicircle of the circle.
- Area of semicircle from quarter circles: $$\frac{1}{2} \pi r^2 = \frac{1}{2} \times 154 = 77 \text{ cm}^2$$
- Area of bottom semicircle of the circle: $$\frac{1}{2} \times 154 = 77 \text{ cm}^2$$
- Since these two semicircles coincide, the overlapping white region is zero.
6. **Therefore, total shaded area:**
- Shaded area = Area of square $-$ (area of two quarter circles + area of circle) + overlapping white regions
- But since the quarter circles and circle overlap inside the square, the shaded area is the area of the square minus the white leaf-shaped regions.
7. **Calculate white leaf-shaped regions:**
- White leaf-shaped regions = area of two quarter circles $-$ area of bottom semicircle of circle
- Both are equal to $77$ cm², so white leaf-shaped regions = $0$ cm².
8. **Hence, total shaded area = area of circle + area of two quarter circles $-$ white leaf-shaped regions = 154 + 77 - 0 = 231$ cm².**
**Final answer:** $$\boxed{231 \text{ cm}^2}$$