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If the radius of a circle is 9.8 cm, then find the following: (i) Circumference of the circle (ii) Area of the circle (iii) Area of the semi-circle (iv) Area of a quadrant of the circle.

User Rousseauo
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Final answer:

The circumference of the circle is approximately 61.44 cm, the area of the circle is approximately 955.03 cm^2, the area of the semi-circle is approximately 477.52 cm^2, and the area of a quadrant of the circle is approximately 238.76 cm^2.

Step-by-step explanation:

(i) Circumference of the circle: The circumference of a circle is given by the formula C = 2πr, where r is the radius. Substituting the given radius of 9.8 cm into the formula, we get C = 2π(9.8) = 19.6π cm, which is approximately 61.44 cm.

(ii) Area of the circle: The area of a circle is given by the formula A = πr^2. Substituting the given radius of 9.8 cm into the formula, we get A = π(9.8)^2 = 301.76π cm^2, which is approximately 955.03 cm^2.

(iii) Area of the semi-circle: The area of a semi-circle is half the area of a full circle. So, the area of the semi-circle is (1/2)A = (1/2)(301.76π) cm^2, which is approximately 477.52 cm^2.

(iv) Area of a quadrant of the circle: The area of a quadrant of a circle is one-fourth of the area of a full circle. So, the area of the quadrant is (1/4)A = (1/4)(301.76π) cm^2, which is approximately 238.76 cm^2.

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User Tandav
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