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calculate angle AOC angle BOD and angle AOE in the adjoining figure it is being given that angle COD equal 90 degree angle BOE = 72 degree and angle AOB is a straight line |
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Answer» ★Calculate ∠AOC, ∠BOD and ∠AOE in the adjoining figure, it is being given that ∠COD = 90°, ∠BOE = 72° and ∠AOB is a straight LINE. Since, AOB is a straight line the sum of all angles on the lower side of AOB at the point O on it, is 180°. ∴ ∠AOB + ∠BOE = 180° ==> 3x + 72° = 180° ==> 3x = (180° – 72°) ==> 3x = 108° ==> X = 108/3 ==> x = 36° Again, AOB is a straight line and O is a point on it. So, the sum of all angles on the upper side of AOB at a point O on it,is 180°. ∴ ∠AOC + ∠COD + ∠DOB = 180° ==> x + 90 + y = 180 [∵ ∠AOC = x°, ∠COD = 90° and ∠DOB = y°] ==> 36 + 90 + y = 180 [∵ x = 36°] ==> 126° + y° = 180° ==> y = 180 – 126 ==> y = 54° ∴ ∠AOC = x° = 36°, ∠BOD = y° = 54° ∠AOC = 3x = (36 × 3) = 108° |
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