Questions: A sector of a circle is shown below.
Calculate the area of the shaded segment. Give your answer to 1 d.p.
Not drawn accurately
Transcript text: A sector of a circle is shown below.
Calculate the area of the shaded segment. Give your answer to 1 d.p.
Not drawn accurately
Solution
Solution Steps
Step 1: Calculate the area of the sector
The area of a sector of a circle is given by the formula (θ/360) * πr², where θ is the angle of the sector in degrees and r is the radius. In this case, θ = 128° and r = 25 m. So, the area of the sector is (128/360) * π * 25² ≈ 701.62 m².
Step 2: Calculate the area of the triangle
The area of the triangle formed by the two radii and the chord can be found using the formula (1/2) * ab * sin(C), where a and b are the lengths of two sides of the triangle, and C is the angle between those sides. In this case, a = b = 25 m (the radii), and C = 128°. So, the area of the triangle is (1/2) * 25 * 25 * sin(128°) ≈ 246.20 m².
Step 3: Calculate the area of the segment
The area of the segment is the difference between the area of the sector and the area of the triangle. Therefore, the area of the segment is 701.62 m² - 246.20 m² ≈ 455.42 m².
Final Answer:
The area of the shaded segment is approximately 455.4 m².