Additional Mathematics – Circular measure | e-Consult
Circular measure (1 questions)
Answer 3
Step 1 – Area of the whole circle:
\[
A_{\text{circle}} = \pi r^{2} = \pi \times 6^{2} = 36\pi\ \text{m}^{2}
\]
Step 2 – Area of the removed sector:
\[
A_{\text{sector}} = \frac{1}{2}r^{2}\theta
= \frac{1}{2}\times 6^{2}\times\frac{\pi}{2}
= \frac{1}{2}\times 36\times\frac{\pi}{2}
= 9\pi\ \text{m}^{2}
\]
Step 3 – Remaining circular area:
\[
A_{\text{remaining}} = 36\pi - 9\pi = 27\pi\ \text{m}^{2}
\]
Step 4 – Area of the rectangular patio:
\[
A_{\text{rect}} = \text{width}\times\text{length}=6\times10=60\ \text{m}^{2}
\]
Step 5 – Total area:
| Component | Exact area | Decimal (m²) |
| Remaining circle | \(27\pi\) | \(27\pi \approx 84.82\) |
| Patio rectangle | \(60\) | \(60.00\) |
| Total | \(27\pi + 60\) | \(144.82\ \text{m}^{2}\) (to two d.p.) |
Thus the combined area is \(\displaystyle 27\pi + 60\) m², which is approximately 144.82 m².