Question

What is the area of the circle whose diameter is 42 cm?

Answer 1

Answer:

1386 cm²

Step-by-step explanation:

given that,

in a circle,

diameter = 42 cm

radius = 1/2 diameter

radius = 1/2 × 42

so,

radius = 21 cm

area of circle = лr²

so,

area of circle = 22/7 × 21 × 21

= 22 × 3 ×21

= 1386 cm²

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EXTRA INFORMATION ABOUT CIRCLE

✔ Circle➡: A circle is the set of all points in a plane that are equidistant from a given point called the center of the circle.

➡Area of circle = лr²

here,

л = 22/7

r = radius of the given circle

➡Circumference --> It is the length of the boundary of the circle.

Circumference = 2лr

Diameter = 2 × radius of the circle

Area of semi circle = лr²/2

Circumference of semi circle = лr + 2r

Area of quadrant of circle = лr²/4

Answer 2

Answer:

1386cm² is the correct answer