A coin of radius 28 mm. What is the area in (a) mm² (b) cm?? ans [(a) 2464 mm² (b) 24.64 cm?]] can any one tel the process
Answers
Answer:
a) 2464 mm²
b) 24.64 cm²
Explanation:
As per the provided information in the given question, we have :
- Radius of coin (r) = 28 mm
We've been asked to calculate area in mm² and in cm².
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Area in mm² :
Area or circle = πr²
⇒ Area of coin = 22/7 × (28 mm)²
⇒ Area of coin = 22/7 × 784 mm²
⇒ Area of coin = 22/1 × 112 mm²
⇒ Area of coin = 22 × 112 mm²
⇒ Area of coin = 2464 mm²
∴ The area of coin in mm² is 2464 mm².
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Area in cm² :
Area or circle = πr²
We need to convert radius into cm first in order to calculate area in cm². 1 mm consists of 0.1 cm. So,
⇒ Radius = 28 mm
⇒ Radius = (28 × 0.1) cm
⇒ Radius = 2.8 cm⠀⠀⠀⠀⠀⠀… ( 1 )
Now, substitute the value of radius from ( 1 ) in the formula of area of coin.
⇒ Area of coin = 22/7 × (2.8 cm)²
⇒ Area of coin = 22/7 × 7.84 cm²
⇒ Area of coin = 22/1 × 1.12 cm²
⇒ Area of coin = 22 × 1.12 cm²
⇒ Area of coin = 24.64 cm²
∴ The area of coin in cm² is 24.64 cm².