Multiple choice

AB is a chord of a circle of radius 14 cm. If the chord AB subtends a right angle at the centre 'O', then the area of triangle AOB (in sq. cm) is:

  1. 112

  2. 98

  3. 198

  4. 56
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Area of a triangle with two sides r and included angle theta is (1/2) * r^2 * sin(theta). Here r=14, theta=90 degrees. Area = (1/2) * 14 * 14 * sin(90) = 0.5 * 196 * 1 = 98.

AI explanation

Triangle AOB is formed by two radii of the circle and the chord AB. Since the angle at the center is 90 degrees, the area of the right-angled triangle AOB is found by the formula half multiplied by base multiplied by height. Plugging in the radius values gives 0.5 multiplied by 14 multiplied by 14, which results in 98 sq. cm.

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