Moderate -0.8 This is a straightforward sector problem requiring recall of two standard formulas (area = ½r²θ and arc length = rθ). Students find θ from the given area, then calculate perimeter as arc length plus two radii. It's more routine than average A-level questions since it involves direct formula application with no conceptual challenges or problem-solving insight required.
1 The diagram shows a sector \(O A B\) of a circle with centre \(O\) and radius 5 cm .
\includegraphics[max width=\textwidth, alt={}, center]{24641e66-b73b-4323-98c8-349727151aba-02_378_451_648_790}
The angle \(A O B\) is \(\theta\) radians and the area of the sector is \(15 \mathrm {~cm} ^ { 2 }\).
Find the perimeter of the sector. [0pt]
[4 marks]
1 The diagram shows a sector $O A B$ of a circle with centre $O$ and radius 5 cm .\\
\includegraphics[max width=\textwidth, alt={}, center]{24641e66-b73b-4323-98c8-349727151aba-02_378_451_648_790}
The angle $A O B$ is $\theta$ radians and the area of the sector is $15 \mathrm {~cm} ^ { 2 }$.\\
Find the perimeter of the sector.\\[0pt]
[4 marks]
\hfill \mbox{\textit{AQA C2 2015 Q1 [4]}}