Question

verify the sum of three angles of a triangle is 180 degree.

topic....
properties or triangle​

Answer 1

✽ Question ✽

Verify the sum of three angles of a triangle is 180°.

✽ To Prove ✽

∠ABC + ∠CAB + ∠ACB = 180°

✽ Construction ✽

Draw the line EF || BC through point ∠A.

✽ Proof ✽

Let ABC is a triangle.

In the given figure,

• ∠ABC = ∠EAD (alternate angles)
• ∠BCA = ∠FAC (alternate angles)

∠EAB + ∠BAC+ ∠FAC = 180° [sum of all linear angles of ∠A]

By substituting ∠EAB with ∠ABC and ∠FAC with ∠BCA, we finally get:-

∠ABC + ∠CAB + ∠ACB = 180°

✽ Hence ✽

∠ABC + ∠CAB + ∠ACB = 180

✽ Proved ✽

The sum of three angles of a triangle is 180°.

Hope this helps you.