Question

two lines ABand CDintersect at a point O if angle AOC equals to 40 degree find the measures of each of the angles angle A ODI Angle B O D and Angle B O C

Answer 1

so the angle BOD =40 (by vertically opposite angle )
angle AOD +AOC = 180 (linear pair )


A OD =180 -40
AOD =140
AOD =BOC =140
(v.o.a.