Circles
Grade 11

Question:

<p>A circle with radius 1 has diameter AB. C lies on this circle such that&nbsp;<span class="math-tex">\(\frac{\widehat{A C}}{\widehat{B C}}\)</span>&nbsp;= 4.&nbsp;<span class="math-tex">\(\overline{A C}\)</span>&nbsp;divides the circle into two parts, and we will label the smaller part Region I. Similarly,&nbsp;<span class="math-tex">\(\overline{B C}\)</span>&nbsp;also divides the circle into two parts, and we will denote the smaller one as Region II. The difference between the areas of Region I and II is : (where&nbsp;<span class="math-tex">\(\widehat{A C}\)</span>&nbsp;represents are AC,&nbsp;<span class="math-tex">\(\overline{A C}\)</span> represents chord AC)</p>
<p style="display:inline"><span class="math-tex">\(\frac{4 \pi}{10}\)</span></p>
<p style="display:inline"><span class="math-tex">\(\frac{3 \pi}{8}\)</span></p>
<p style="display:inline"><span class="math-tex">\(\frac{3 \pi}{10}\)</span></p>
<p style="display:inline"><span class="math-tex">\(\frac{ \pi}{4}\)</span></p>

Step-by-Step Solution

Key Concept: Determine the central angles for chords AC and BC using the given arc ratio and calculate the difference between their circular segment areas using the formula $A = \frac{1}{2}r^2(\theta - \sin\theta)$.
<p><span class="math-tex">$\frac{3 \pi}{10}$</span></p>
Correct Answer: C

Master Circles with Mathbee

Practice this topic under real exam conditions with strict timers, or ask our AI Mentor to explain the concepts step-by-step.

Start Practicing for Free