7. Given AB I CD (see Figure 20.20), can you tell withcentainty that A

1.	7. Given AB I CD (see Figure 20.20), can you tell withcentainty that AOBA AOCD?vin, 20.20
Answer» Given : AB \|\| CD In ∆ OBA and ∆ OCD angle AOB=angle DOC(vertically opposite) angle OAB= angle ODC ( Alternate angle) angle OCD = angle OBA ( Alternate angle) Though AAA rule not exist, no we can not say certainly but if a corresponding side are equal we can use a criterion.

7. Given AB I CD (see Figure 20.20), can you tell withcentainty that AOBA AOCD?vin, 20.20

Answer»

Given : AB || CD

In ∆ OBA and ∆ OCD

angle AOB=angle DOC(vertically opposite)

angle OAB= angle ODC ( Alternate angle)

angle OCD = angle OBA ( Alternate angle)

Though AAA rule not exist, no we can not say certainly but if a corresponding side are equal we can use a criterion.