Question

the three exterior angles of triangle are 130 degree 140 degree X degree and X degree is the options given here are 90 degree 100 degree and 10 degree and 20 degree

Answer 1

Answer is 90°

Here is the proof.

Answer 2

take the sides as : A,B,C.

A=>130+x=180 [linear pair]

=50

B=>140+x=180 [linear pair]

=40

in triangle ABC,

                    A+B+C=180 [asp]

                    50+40+C=180

                         90+c=180

                            C=90

so X=C+C1

     X=90+X

          X=90