Question

hi there

Two angles of a parallelogram are in the ratio 5:7. If the
bigger angle is halved, what will be the ratio of the angles
of the new parallelogram obtained?

Answer 1

let one angle be x

so other angle would be 180 -x

5/7 = x/180-x

Apply compondendo and dividendo

5-7/5+7 = x-180+x/x+180-x

-2/12= 2x-180/180

-1/6= x-90/90

-90= 6x-540

-90+540= 6x

450 = 6x

x= 75
so other angle= 180-75= 105

When bigger is halved that means 105/2= 52.5

Smaller angle becomes = 180 -52.5= 127.5

ratio becomes = 127.5/52.5= 2.43= 243/100