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if two parallel lines are intersected by a transversal then prove that the bisectors of the interior angles on both sides of transversal form a rectangle |
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Answer» Step-by-step explanation: f AB and CD are TWO parallel line intersected by a transverse L X and Y are the point of INTERSECTION of L with AB and CD respectively. XP, XQ, YP and YQ are the angle bisector of ∠AXY,∠BXY,∠CYXand∠DYX AB∥CD and L is transversal. ∴∠AXY=∠DYX (pair of alternate angle) ⇒ 2 1
∠AXY= 2 1
∠DXY ⇒∠1=∠4(∠1= 2 1
∠AXYand∠4= 2 1
∠DXY) ⇒ YQ PX
(If a transversal intersect two line in such a way that a pair of alternate interior angle are equal, then the two line are parallel) (1) Also ∠BXY=∠CYX (pair of alternate angle) ⇒ 2 1
∠BXY= 2 1
∠CYX ⇒∠2=∠3(∠2= 2 1
∠BXYand∠3= 2 1
∠CYX) ⇒ XQ PY
(If a transversal intersect two line in such a way that a pair of alternate interior angle are angle, then two line are parallel) (2) from (1) and (2), we get PXQY is parallelogram ....(3) ∠CYD=180 0
⇒ 2 1
∠CYD= 2 180
=90 0
⇒ 2 1
(∠CYX+∠DYX)=90 0
⇒ 2 1
∠CYX+ 2 1
∠DYX=90 0
⇒∠3+∠4=90 0
⇒∠PYQ=90 0 .......(4)
So using (3) and (4) we conclude that PXQY is a rectangle. Hence proved. |
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