Question

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Q7If three angles of a quadrilateral are equal
and fourth angle is 120°, find the measure of
each equal angle.​

Answer 1

Answer:

3x+120=360

3x=360-120

3x=240

x=80

Answer 2

Given that,

• The measure of the fourth angle is 120°.

☯ Let the measure of each angle be x.

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⠀⠀⠀$\dag\;{\underline{\frak{As \ we \ know \ that,}}}$⠀⠀

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• Sum of all angles of the Quadrilateral is 360°.

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Therefore,

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$:\implies\sf x + x + x + 120^{\circ} = 360^{\circ}\\\\\\:\implies\sf 3x + 120^{\circ} = 360^{\circ} \\\\\\:\implies\sf 3x = 360^{\circ} - 120^{\circ} \\\\\\:\implies\sf 3x = 240^{\circ}\\\\\\:\implies\sf x = \cancel\dfrac{240}{3}\\\\\\:\implies{\underline{\boxed{\frak{\purple{x = 80^{\circ}}}}}}\:\bigstar$

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$\therefore\:{\underline{\sf{ Hence, \ measure \ of \ each \ equal \ angle \:is\: \bf{80^{\circ}}.}}}$