Question

State which of the following are triangles:
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Answer 1

Answer:

a) The sum of all angles of a triangle is 180 degree

If ABC is a triangle

A+B+C=180

but

A+B+C=150

therefore it is not a triangle

similar method can be used for second question sum of the angles is 60+60+60=180

Answer 2

Answer:

(c)

Step-by-step explanation:

we know that , sum of all angles of a triangle is 180⁰

so A+B+C =180⁰

Now in (a)

A+B+C

=40⁰+50⁰+60⁰=150⁰

in (a) sum of all angles is not 180 so its is not a triangle

(C)

A+B+C

=60⁰+60⁰+60⁰=180⁰

In (c) sum of all angles is 180⁰ so it is a triangle