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Geometry/Formular to Calculate Area of a Shaded Portion


Sir, what is the exact formular that can be use to find area of a shaded portion of any shape? For example, a fan which is in the shape of radius 35cm. The unshaded part of the fan is of radius 26.25cm . Calculate the area of the shaded part of the fan.

Hi John,

This depends completely on what the shape is.  If the shape is a rectangle or a triangle or circle (for instance) you will need to use the corresponding formula.  If the shape is irregular, then you may be able to subdivide it into portions that are regular shapes and add their areas.

If you can include a diagram, I may be able to help you with your particular question.



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Azeem Hussain


I welcome your questions on algebra, 2D and 3D geometry, parabolic functions and conic sections, and any other mathematical queries you may have.


4 years as a drop-in and by-appointment tutor at Champlain College. Private tutor for dozens of clients over the past 8 years.

CALPHAD: Computer Coupling of Phase Diagrams and Thermochemistry

Bachelor of Science, Major Mathematics and Major Economics, McGill University, 2014. Diploma of Collegiate Studies; Pure and Applied Science, Champlain College Saint-Lambert, 2010.

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