Multiple choice

A chord of a circle of diameter 20 cm subtends a right angle at the centre. Find the area of the minor sector.

  1. 575 7 cm2

  2. 2200 7 cm2

  3. 650 7 cm2

  4. 550 7 cm2

  5. NA
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The diameter is 20 cm, so the radius is 10 cm. A right angle at the centre gives a sector of 90 degrees, whose area is (90/360) × pi × 10^2 = 25pi = 550/7 cm^2 using pi = 22/7. The numerical answer matches option D, although its unit should be cm^2.

AI explanation

Given the diameter is 20 cm, the radius is 10 cm. Using the sector area formula, Area = (angle/360) * pi * r^2, we substitute the 90 degree angle and radius. The calculation gives (90/360) * (22/7) * 10^2 = 550/7 cm^2.

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