in question 8 of ex 8.1 cant i prove diagonal BD bisects angle B and angle D by naming them separtely for example as angle 5 and 6 and angle D As 7 and 8 or as we have given AC bisects angle A and C so instead of naming them as angle 1 and 2 ,3 and 4 cant we name B and D as angle 1 and 2 thankyou