This question is similar to Chapter 11 Class 10 Areas related to Circles - Ex 11.1

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https://www.teachoo.com/1853/547/Ex-12.2--4---A-chord-of-a-circle-of-radius-10-cm-subtends/category/Ex-12.2/

 

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Question 24 (B) Find the area of the major segment (in terms of πœ‹) of a circle of radius 5 cm, formed by a chord subtending an angle of 90˚ at the centre.Given that OA = OB = radius = 5 cm ΞΈ=90Β° First lets’ find Area of minor Segment Area of minor segment = Area of sector OAPB – Area of Ξ”AOB Area of sector OAPB Area of sector OAPB = ΞΈ/(360Β°)Γ— Ο€r2 = πŸ—πŸŽ/πŸ‘πŸ”πŸŽ Γ— 𝝅 Γ— (πŸ“)𝟐 = 1/4 Γ— πœ‹ Γ— 25 = πŸπŸ“π…/πŸ’ cm2 Area of Ξ”AOB Now, Ξ”AOB is a right triangle, where ∠ O = 90Β° having Base = OA & Height = OB Area of Ξ” AOB = 1/2 Γ— Base Γ— Height = 𝟏/𝟐 Γ— OA Γ— OB = 1/2 Γ— 5 Γ— 5 = πŸπŸ“/𝟐 cm2 Now, Area of minor segment = Area of sector OAPB – Area of Ξ”AOB = (πŸπŸ“π…/πŸ’βˆ’πŸπŸ“/𝟐) Area of major segment Area of major segment = Area of circle – Area of minor segment = 𝝅𝒓^πŸβˆ’ (πŸπŸ“π…/πŸ’βˆ’πŸπŸ“/𝟐) = πœ‹ Γ— 5^2βˆ’ (πŸπŸ“π…/πŸ’βˆ’πŸπŸ“/𝟐) = 25πœ‹βˆ’ (πŸπŸ“π…/πŸ’βˆ’πŸπŸ“/𝟐) = πŸπŸ“π…βˆ’πŸπŸ“π…/πŸ’+πŸπŸ“/𝟐 = 25πœ‹(1βˆ’πŸ/πŸ’)+πŸπŸ“/𝟐 = 25πœ‹ Γ—3/4+πŸπŸ“/𝟐 = πŸ•πŸ“π…/πŸ’+πŸπŸ“/𝟐

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Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 15 years. He provides courses for Maths, Science and Computer Science at Teachoo