# math

posted by
**nbvhj**
.

Prove the following: if, in a triangle ABC,BA =CB

O in atriangle

mÐ BAO = mÐ OAC = 20°,

mÐ ACO = 10°,

and mÐ OCB = 30°,

then mÐ OBC = 80°.

posted by
**nbvhj**
.

Prove the following: if, in a triangle ABC,BA =CB

O in atriangle

mÐ BAO = mÐ OAC = 20°,

mÐ ACO = 10°,

and mÐ OCB = 30°,

then mÐ OBC = 80°.