Geometry Questions

Multiple choice
  1. $\displaystyle \frac{\pi r^{2}}{2}$
  2. $\displaystyle \left ( \pi -\frac{1}{2} \right )r^{2}$
  3. $\left ( \pi -1 \right )r^{2}$
  4. $\left ( \pi -2 \right )r^{2}$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A right isosceles triangle inscribed in a circle has a hypotenuse equal to the diameter (2r). The legs are r * sqrt(2). The area of the triangle is (1/2) * base * height = (1/2) * (r * sqrt(2)) * (r * sqrt(2)) = r^2. The remaining area is the circle area minus triangle area: pi * r^2 - r^2 = (pi - 1) * r^2.

Multiple choice
  1. $\displaystyle \left ( \pi -2 \right )x^{2} $
  2. $\displaystyle \left ( \pi -2 \right )\frac{x^{2}}{2} $
  3. $\displaystyle 2\left ( \pi -2 \right )x^{2} $
  4. $\displaystyle \left ( \pi -2 \right )\frac{x^{2}}{4} $
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The square is inscribed in a circle, so the diagonal of the square equals the diameter of the circle. Diagonal = x*sqrt(2), so radius r = (x*sqrt(2))/2. Area of circle = pi * r^2 = pi * (x^2 / 2). Area of square = x^2. The difference is x^2(pi/2 - 1) = (pi - 2) * x^2 / 2.

Multiple choice
  1. Area of major segment$=285.5cm^2$,  Area of minor segment$=28.5cm^2$
  2. Area of major segment$=232cm^2$,  Area of minor segment$=24.6cm^2$
  3. Area of major segment$=212.7cm^2$,  Area of minor segment$=32.5cm^2$
  4. Area of major segment$=196.2cm^2$,  Area of minor segment$=21.3cm^2$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

For a circle with radius 10 and a 90-degree central angle, the area of the minor segment is (pi*r^2 * 90/360) - (0.5 * r^2 * sin(90)) = (3.14 * 100 / 4) - 50 = 78.5 - 50 = 28.5 cm^2. The major segment area is total area - minor segment = 314 - 28.5 = 285.5 cm^2.

Multiple choice
  1. $45.27\ cm^{2}$
  2. $40.27\ cm^{2}$
  3. $40.8\ cm^{2}$
  4. $44.27\ cm^{2}$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Area of segment = Area of sector - Area of triangle = (theta/360 * pi * r^2) - (1/2 * r^2 * sin(theta)). For theta=60, area = (60/360 * 3.14 * 21^2) - (sqrt(3)/4 * 21^2) = (1/6 * 3.14 * 441) - (0.433 * 441) = 230.86 - 190.95 = 39.91. Close to 40.27.