1. **Problem statement:** We have an oval track ABCD with given lengths |AB| = 20 cm and |BC| = 14 cm. We need to calculate:
(i) The perimeter of the track.
(ii) The area of the track.
Take \(\pi = \frac{22}{7}\).
2. **Understanding the shape:** The track is an oval, which can be approximated as an ellipse with major axis length \(2a = 20\) cm and minor axis length \(2b = 14\) cm.
So, \(a = \frac{20}{2} = 10\) cm and \(b = \frac{14}{2} = 7\) cm.
3. **Formulas:**
- Perimeter (circumference) of an ellipse does not have a simple exact formula, but Ramanujan's approximation is very accurate:
$$ P \approx \pi \left[ 3(a+b) - \sqrt{(3a + b)(a + 3b)} \right] $$
- Area of an ellipse:
$$ A = \pi a b $$
4. **Calculate the perimeter:**
Calculate each term:
\(3(a+b) = 3(10 + 7) = 3 \times 17 = 51\)
\(3a + b = 3 \times 10 + 7 = 30 + 7 = 37\)
\(a + 3b = 10 + 3 \times 7 = 10 + 21 = 31\)
Calculate the square root term:
$$ \sqrt{37 \times 31} = \sqrt{1147} $$
Approximate \(\sqrt{1147} \approx 33.87\) (rounded to two decimals).
Now substitute into the perimeter formula:
$$ P \approx \pi (51 - 33.87) = \pi \times 17.13 $$
Using \(\pi = \frac{22}{7} \approx 3.142857\):
$$ P \approx 3.142857 \times 17.13 \approx 53.82 \text{ cm} $$
5. **Calculate the area:**
$$ A = \pi a b = \frac{22}{7} \times 10 \times 7 $$
Simplify:
$$ A = \frac{22}{7} \times \cancel{10} \times \cancel{7} = 22 \times 10 = 220 \text{ cm}^2 $$
6. **Final answers:**
- Perimeter \(\approx 53.82\) cm
- Area \(= 220\) cm\(^2\)
Ellipse Track 01E021
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