Multiple choice

The perimeter and the area of a semi-circular plate of radius 25 cm are, respectively (Take $\pi $ = 3.14)

  1. 625.5 cm, 981.25 $cm^2$
  2. 128.5 cm, 981.25 $cm^2$
  3. 412.5 cm, 981.25 $cm^2$
  4. 188.5 cm, 981.25 $cm^2$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Perimeter of semicircle = pi*r + 2r = 3.14*25 + 50 = 78.5 + 50 = 128.5 cm. Area = (1/2)*pi*r^2 = 0.5 * 3.14 * 625 = 981.25 cm^2.

AI explanation

The perimeter of a semi-circular plate is given by the formula P = pi * r + 2 * r, which includes the curved arc and the straight diameter. Substituting the radius of 25 cm gives P = 3.14 * 25 + 2 * 25 = 78.5 + 50 = 128.5 cm. The area of the semi-circular plate is half the area of a full circle, calculated as A = 0.5 * pi * r^2. Substituting the values gives A = 0.5 * 3.14 * 25^2 = 981.25 cm^2.

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