The area of a sector a circle with diameter 12cm is 66cm². If the sector is folded to form a cone, calculate the radius of the base of the cone [Take \(\pi = \frac{22}{7}\)]

3.0cm

3.5cm

7.0cm

7.5cm

Correct answer is B

diameter = 12cm

radius = \(\frac{12}{2}\)cm = 6cm

area of sector = 66cm²

area of sector = area of cone

66 = \(\pi rl\)

66 = \(\frac{22}{7} \times r \times 6\)

divide both sides by 6

11 = \(\frac{22}{7}r\)

22r = 11 x 7

r = \(\frac{77}{22}\)

= 3.5cm

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The area of a sector a circle with diameter 12cm is 66cm2. If the sector is folded to form a cone, calculate the radius of the base of the cone [Take \(\pi = \frac{22}{7}\)]

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The area of a sector a circle with diameter 12cm is 66cm². If the sector is folded to form a cone, calculate the radius of the base of the cone [Take \(\pi = \frac{22}{7}\)]