Question

111. In a quadrilateral ABCD; angles A, B, C and
D are in the ratio 3 : 2:1: 4.
Prove that AD is parallel to BC.
Guys please answer fast tomorrow is my exam.
Who answers first with correct answer I will mark them as brainliest and follow them and also thank their answers​

Answer 1

Answer-:

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Given:

The angles of quadrilateral ABCD are in the ratio 3 : 2 : 1 : 4

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Let the angles of quadrilateral ABCD be 3x, 2x, x and 4x respectively.

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=) We know that sum of angles of

quadrilateral is 360°

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=) 3x + 2x + x + 4x = 360°

=) 10x =360⁰

=) x = 36⁰

=) ∠A = 108⁰,

∠B = 72⁰,

∠C = 36⁰,

∠D = 144⁰

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Now, AD and BC are two lines and ∠A +

∠B = ∠C + ∠D = 180⁰

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Hence AD is parallel to BC

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[∴ If the sum of interior angle on the same

side of traversal is supplementary, then the line

are parallel]

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