Home > Areas Related to Circles > CBSE_NCERT_EXEMPLAR_CH10 > 29738b39-6414-5460-b2c8-8d8a43d6cc7b
Not the exact question you were looking for?

Paste your question to our Mathbee AI Mentor below to get an instant step-by-step solution.

Areas Related to Circles
NCERT Exemplar Ch 10
CBSE_NCERT_EXEMPLAR_CH10
Grade 10

Question:

In a circle of radius $21\text{ cm}$, an arc subtends an angle of $60^\circ$ at the centre. Find:
(i) length of the arc
(ii) area of sector formed by the arc.

Step-by-Step Solution

Key Concept: Arc length $= \dfrac{\theta}{360^\circ} \times 2\pi r$. Sector area $= \dfrac{\theta}{360^\circ} \times \pi r^2$.
Stepwise Solution:

(i) Arc length $= \dfrac{60}{360} \times 2 \times \dfrac{22}{7} \times 21 = \dfrac{1}{6} \times 132 = 22\text{ cm}$. [1.0 Mark]

(ii) Sector area $= \dfrac{60}{360} \times \dfrac{22}{7} \times 21 \times 21 = \dfrac{1}{6} \times 1386 = 231\text{ cm}^2$. [1.0 Mark]

Marking Scheme:

• Arc length $= 22\text{ cm}$: 1.0 Mark
• Sector area $= 231\text{ cm}^2$: 1.0 Mark

Correct Answer:
Mathbee AI Mentor (Free Demo)

Confused by the solution? Ask the AI to explain a specific step, tell you where you went wrong, or break down the key trap in this question.

Master Areas Related to 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