203k views
15 votes
The options are
40
80
120
140

The options are 40 80 120 140-example-1

1 Answer

5 votes

Here we go ~

According to given figure,


\qquad \sf  \dashrightarrow \: \angle ABC + 60° = 180°


\qquad \sf  \dashrightarrow \: \angle ABC = 180 \degree - 60 \degree

[ By linear pair ]


\qquad \sf  \dashrightarrow \: \angle ABC = 120 \degree

now, we can see that :


\qquad \sf  \dashrightarrow \: \angle ABC + \angle BAC = \angle 1

[ By Exterior angle property of Triangle ]


\qquad \sf  \dashrightarrow \: \angle 1 = 20 \degree + 120 \degree


\qquad \sf  \dashrightarrow \: \angle 1 = 140 \degree

User Scrhartley
by
4.3k points