Question

3
کے
2) If two angles of a triangle
its third angle is!
A a triangle are 30° and to, then
a) 70° b) 800 c) 100°C d) 1800​

Answer 1

Let in a triangle ABC,the sum of two angles is equal to the third angle.

i.e. ∠A=∠B+∠C    ....(1)

We know ∠A+∠B+∠C=1800

⇒∠A+∠A=1800    ....From (1)

⇒2∠A=1800

⇒∠A=1900    (Right angle)

Hence, triangle ABC is a right-angled triangle.