Question

The three angles of a Quadrilateral are 100° , 80° and 70° .Find the 4th Angle .​

Answer 1

Given :

• 1st Angle of Quadrilateral = 100°
• 2nd Angle of Quadrilateral = 80°
• 3rd Angle of Quadrilateral = 70°

To Find :

• Find the 4th Angle

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SolutioN :

❒ We know That :

• Sum of Angles(Quadrilateral) = 360°

❒ Calculating the 4th Angle :

$➳ \qquad \;$ ∠1 + ∠2 + ∠3 + ∠4 = 360°

$\\ ➳ \qquad \;$ 100° + 80° + 70° + ∠4 = 360°

$\\ ➳ \qquad \;$ 180° + 70° + ∠4 = 360°

$\\ ➳ \qquad \;$ 250° + ∠4 = 360°

$\\ ➳ \qquad \;$ ∠4 = 360° - 250°

$\\ ➳ \qquad \; {\purple{\underline{\underline{\sf{ ∠4 = 110° }}}}}$

❒ Therefore :

4th Angle of the Quadrilateral is 110° .

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