Find the area of a circle whose diameter is
Q(i) 28 cm.
(ii)1.4 m. 

Answer

To find the area of a circle given its diameter, we can follow these steps:

### Step-by-Step Solution:

**Step 1: Calculate the radius from the diameter.**

For (i) Diameter = 28 cm:
- Radius (r) = Diameter / 2 = 28 cm / 2 = 14 cm

For (ii) Diameter = 1.4 m:
- Convert 1.4 m to cm (since 1 m = 100 cm):
Diameter = 1.4 m = 1.4 * 100 cm = 140 cm
- Radius (r) = Diameter / 2 = 140 cm / 2 = 70 cm

**Step 2: Use the formula for the area of a circle.**

The formula for the area (A) of a circle is:
\[ A = \pi r^2 \]

For (i):
- Area = π * (14 cm)²
- Using π ≈ 22/7:
Area = (22/7) * (14 * 14)
- Calculate 14 * 14 = 196
- Area = (22/7) * 196
- Area = 22 * 28 = 616 cm²

For (ii):
- Area = π * (70 cm)²
- Area = (22/7) * (70 * 70)
- Calculate 70 * 70 = 4900
- Area = (22/7) * 4900
- Area = 22 * 700 = 15400 cm²

### Final Answers:
(i) The area of the circle with a diameter of 28 cm is **616 cm²**.
(ii) The area of the circle with a diameter of 1.4 m (or 140 cm) is **15400 cm²**.

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