Question

Prove that the sum of the angles of any triangle PQR Is two right angles

Answer 1

Answer:

Step-by-step explanation:draw a triangle with angles x,y and z

Now construct a line parallel to a side now x=X and y=Y (interior alternate angle)

Now x+y+z=180(linear)

Hence proved

Answer 2

two right angles is nothing but 180 °

construction draw a line APB parallel to QR

angle A P Q + angle QPR + angle RPQ = 180° ( straight line) ...(1)

angle A P Q = angle PQR... (2) (corresponding angles )

similarly Angle B P R = angle PRQ..... (3)

substituting(2) and(3) in (1) we get

angle pqr + angle QPR + angle prq = 180°

hence proved that the sum of the angles of a triangle is two right angles that is 180 °