Figure 2 shows a plan view of a garden - Edexcel - A-Level Maths Pure - Question 7 - 2013 - Paper 4
Question 7
Figure 2 shows a plan view of a garden.
The plan of the garden ABCDEA consists of a triangle ABE joined to a sector BCDE of a circle with radius 12 m and centre B.
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Worked Solution & Example Answer:Figure 2 shows a plan view of a garden - Edexcel - A-Level Maths Pure - Question 7 - 2013 - Paper 4
Step 1
(a) the area of the garden, giving your answer in m², to 1 decimal place.
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Answer
To find the area of triangle ABE, we can use the formula:
Area=21×AB×AE×sin(angle ABE)
Given:
(AB = 23 , m)
(\text{angle ABE} = 0.64 , radians)
We need to find (AE). Using the sine rule:
sin(angle ABE)AE=sin(CDE)AB
Calculating the area:
Area=21×23×12×sin(0.64)≈26.3m2
Final answer:
The area of the garden is approximately 26.3 m².
Step 2
(b) the perimeter of the garden, giving your answer in metres, to 1 decimal place.
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Answer
The perimeter consists of the sum of the lengths of all the sides:
Side AB: 23 m
Side BC: 12 m
The arc length of the sector BCDE: We need to calculate this using the formula:
extArcLength=r×θ
where (r = 12 , m) and (\theta = 0.64). Thus, the arc length is:
Arc Length=12×0.64≈7.68m
Now, adding all components for the perimeter:
P=AB+BC+Arc Length=23+12+7.68=42.68m
Final answer:
The perimeter of the garden is approximately 42.7 m.