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Question
In the figure, given below, find: ∠ABC. Show steps of your working.
Solution
∠ADC + ∠ABC = 180°
(Sum of opposite angles of a cyclic quadrilateral is 180°)
`=>` ∠ABC = 180° – 75° = 105°
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To prove: ∠DCE ≅ ∠BAD
Proof: `square` + ∠BCD = `square` .....[Angles in linear pair] (I)
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