E-Math - Arc Length and Area of Sector - Finding Angles and Area of Shaded Area

E-Math - Arc Length and Area of Sector  

Finding Angles and Area of Shaded Area 

Topic:Mensuration

In Part a) I drew a horizontal line AE with the purpose of creating a right
angle triangle, so that I may use trigonometric ratio i,e. tan, sin or cos to
find the unknown angles of the sectors.

I Part b) I used the formula \(\frac{\theta }{{{{360}^O}}} \times \pi {r^2}\)to find the Area of Sectors BAF and CDF.
To find the area of trapezium, I used the formula \(\frac{1}{2} \times (sum\;of\;parallel\;sides) \times height\;\).
The height is actually line BC (yes...the height can be horizontal) and the parallel sides
are lines AB and DC.

There is no need to find for arc length in this question, just find the area of sectors.

Additional Math (A-Maths) and Math (E-Math) Tutor in Woodlands, Chua Chu Kang,
Sembawang, Bukit Panjang, Yishun and Johor Bahru.

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About Unknown

I created this Blog after my students told me that there is very little information about how to solve GCE O Level Math and Additional Math (A-Math) questions on the internet. Even if they manage to find, the solution were for very basic questions. I am a Full-time Math Tutor in Singapore. I tutor mainly in Northern Singapore (Woodlands, Chua Chu Kang, Bukit Panjang, Yishun and Sembawang). I also tutor in Johor Bahru.