Question

Proof that- The sum of the angles of a quadrilateral is 360°​

Answer 1

Explanation:

when we draw a deaw diagonal it forms two triangles

and the sum of sides of triangles is 180°.Therefore the total angle sun of Quadrilateral is 360°

Answer 2

quadrilateral PQRS.

Join QS.

To prove: ∠P + ∠Q + ∠R + ∠S = 360º

Proof:

Consider triangle PQS, we have,

⇒ ∠P + ∠PQS + ∠PSQ = 180º ... (1) [Using Angle sum property of Triangle]

Similarly, in triangle QRS, we have,

⇒ ∠SQR + ∠R + ∠QSR = 180º ... (2) [Using Angle sum property of Triangle]

On adding (1) and (2), we get

∠P + ∠PQS + ∠PSQ + ∠SQR + ∠R + ∠QSR = 180º + 180º

⇒ ∠P + ∠PQS + ∠SQR + ∠R + ∠QSR + ∠PSQ = 360º

⇒ ∠P + ∠Q + ∠R + ∠S = 360º [Hence proved]