Question

Need help please.

Explain your steps.
If the measure of base angle BAC is 80 degrees, what is the measure of angle ABC? Thanks

Answer 1

Hi !

BAC is a triangle isocele in B so :
`\widehat{BAC}=\widehat{BCA}=80\°\\`

The sum of the angles of any triangle is 180°.


`180-80*2=180-160=20`


`\boxed{\boxed{\widehat{ABC}=20\°}}`