[tex]\bold\color{plum}\tt \: Answer \: \: 1 :[/tex]
Diameter = 4 cm
Radius = Diameter/2 = 2 cm
Area of circle :
[tex] = \pi{r}^{2} [/tex]
[tex] = 3.14 \times 2 \times 2[/tex]
[tex] = 3.14 \times 4[/tex]
[tex] = 12.56 \: {cm}^{2} [/tex]
Circumference of circle :
[tex] = 2\pi r[/tex]
[tex] = 2 \times 3.14 \times 2[/tex]
[tex] = 12.56 \: \: {cm}^{2} [/tex]
Therefore,
Diameter = 4 cm
Radius = 2 cm
Area = 12.56 cm²
Circumference = 12.56 cm
[tex]\bold{\color{plum}\tt \: Answer \: \: 2 :}[/tex]
Circumference = 15 feet (given)
Radius :
[tex] = 2\pi r[/tex]
[tex] = 2 \times \frac{22}{7} \times r = 15[/tex]
[tex] = \frac{44}{7} \times r = 15[/tex]
[tex] = 44r = 15 \times 7[/tex]
[tex] = 44r = 105[/tex]
[tex] = r = \frac{105}{44} [/tex]
[tex] = r = 2.38 \: feet[/tex]
Diameter = r×2 = 2.38 × 2 = 4.76 feet
Area :
[tex] = \pi {r}^{2} [/tex]
[tex] = 3.14 \times 2.38 \times 2.38[/tex]
[tex] = 17.78 \: {ft}^{2} [/tex]
Therefore,
Diameter = 4.76 feet
Radius = 2.38 feet
Area = 17.78 ft²
Circumference = 15 feet
[tex]\color{plum}\tt \: Answer \: \: 3 :[/tex]
Diameter = 2 cm (given)
Radius = D/2 = 2/2 = 1 cm
Circumference :
[tex] = 2 \pi r[/tex]
[tex] = 2 \times 3.14 \times 1[/tex]
[tex] = 6.28 \: feet[/tex]
Area :
[tex] = \pi {r}^{2} [/tex]
[tex] = 3.14 \times 1 \times 1[/tex]
[tex] = 3.14 \: {ft}^{2} [/tex]
Therefore,
Diameter = 2 cm
Radius = 1 cm
Area = 3.14 ft²
Circumference = 6.28 feet
[tex]\color{plum}\tt \: Answer \: \: 4 :[/tex]
Radius = 4.3 mm
Diameter = r×2 = 4.3 × 2 = 8.6 mm
Circumference :
[tex] = 2\pi r[/tex]
[tex] = 2 \times 3.14 \times 4.3[/tex]
[tex] = 27 \: mm[/tex]
Area :
[tex] = \pi {r}^{2} [/tex]
[tex] = 3.14 \times 4.3 \times 4.3[/tex]
[tex] = 3.14 \times 18.49[/tex]
[tex] = 58.05 \: {mm}^{2} [/tex]
Therefore,
Diameter = 8.6 mm
Radius = 4.3 mm
Area = 58.95 mm²
Circumference = 27 mm
