Mensuration Questions

Multiple choice
  1. $45m^{2}$
  2. $54 m^2$
  3. $50 m^2$
  4. $48 m^2$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The square base that fits inside a circular cross-section has diagonal 3 m, so its side is 3/sqrt(2) m. The remaining timber is a square prism with volume 45 cubic m, not 45 square m, so the numerical value matches but the stated unit is wrong.

Multiple choice
  1. $10m$
  2. $15cm$
  3. $20m$
  4. $24cm$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The area of the new circle is the sum of the areas of the two given circles: pi*R^2 = pi*(d1/2)^2 + pi*(d2/2)^2. Substituting diameters 16m and 12m gives R^2 = 8^2 + 6^2 = 64 + 36 = 100, so R = 10m.

Multiple choice
  1. $\displaystyle \frac{144}{3}cm^{2}$
  2. $\displaystyle \frac{77}{3}cm^{2}$
  3. $\displaystyle \frac{154}{7}cm^{2}$
  4. None

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The area of a sector of a circle is calculated using the formula (theta / 360) * pi * r^2. Substituting the given values of theta = 60 degrees and r = 7 cm, we get (60 / 360) * (22 / 7) * 7^2. This simplifies to (1 / 6) * 154, which reduces to 77 / 3 square centimeters.

Multiple choice
  1. $\displaystyle 22\sqrt{115}m^{2}$
  2. $\displaystyle 310m^{2}$
  3. $\displaystyle 22\sqrt{373}m^{2}$
  4. $\displaystyle 276m^{2}$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Interpreting the stated volume as 924 m^3, use (1/3)pi r^2 x 18 = 924 to obtain r = 7 m. The slant height is sqrt(7^2 + 18^2) = sqrt(373), so the lateral area is pi x 7 x sqrt(373) = 22sqrt(373) m^2.

Multiple choice
  1. 44 lit

  2. 88 lit

  3. 66 lit

  4. None of the above

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Volume = cross-section area * flow rate * time. Area = pi * r^2 = pi * (2 cm)^2 = 4 * pi cm^2. Flow rate = 7 m/min = 700 cm/min. Time = 10 min. Volume = 4 * pi * 700 * 10 = 28,000 * pi cm^3. Since 1000 cm^3 = 1 liter, Volume = 28 * pi liters = 28 * 3.14 = 87.92 liters, which is approx 88 liters.

Multiple choice
  1. $\displaystyle 4\left ( 9-\pi \right )cm^{2}$
  2. $\displaystyle 9\left ( 4-\pi \right )cm^{2}$
  3. $\displaystyle 5\left ( 6-\pi \right )cm^{2}$
  4. $\displaystyle 6\left ( 5-\pi \right )cm^{2}$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Four circles of radius r=3 form a square of side 2r=6 connecting their centers. The area of the square is 6*6 = 36. The area of the four sectors inside the square is 4 * (90/360 * pi * r^2) = pi * r^2 = 9*pi. The region between them is 36 - 9*pi = 9(4-pi).

Multiple choice
  1. $\displaystyle 20\sqrt{2},20\sqrt{3},10$
  2. $\displaystyle \frac{10\sqrt{3}}{3},\frac{10\sqrt{2}}{3},\frac{10}{3}$
  3. $\displaystyle 10\sqrt{3},10\sqrt{2},10$
  4. $17,14,10$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The total area is pi*R^2 = pi*20^2 = 400*pi. Dividing into 4 equal parts means each ring/circle has area 100*pi. The radii r1, r2, r3 satisfy pi*r3^2 = 100*pi (r3=10), pi*r2^2 = 200*pi (r2=10*sqrt(2)), and pi*r1^2 = 300*pi (r1=10*sqrt(3)).