Fig. 7.32A.ABC and DBC are two isoscelcs triangles on thesame base BC

1.	Fig. 7.32A.ABC and DBC are two isoscelcs triangles on thesame base BC (see Fig. 7.33). Show thatangle ABD=angle ACD.
Answer» In ∆ ABC angle ABC = angle ACB ....(1) In ∆BDCangle DBC = angle DCB ......(2) adding (1) and (2)angle ABC + angle DBC = angle ACB + angle DCBsoangle ABD = angle ACD

Fig. 7.32A.ABC and DBC are two isoscelcs triangles on thesame base BC (see Fig. 7.33). Show thatangle ABD=angle ACD.

Answer»

In ∆ ABC angle ABC = angle ACB ....(1)

In ∆BDCangle DBC = angle DCB ......(2)

adding (1) and (2)angle ABC + angle DBC = angle ACB + angle DCBsoangle ABD = angle ACD