Question

In a parallelogram prove that sum of any two consecutive angles is 180°

Answer 1

let the angles be a and b
as opposite sides are equal the sides are
a,a,b,b
sum of the sides in a quadrilateral is 360°
therefore a+a+b+b = 360°
2(a+b) = 360°
a+b = 180°
hence, the consecutive angles in a parallelogram is 180°...
hope this helped you