Question

Give the ans. with complete explanations.​

Answer 1

Required Answer:-

Given to prove:

• If, in a ΔABC, ∠A = ∠B + ∠C, prove that ΔABC is a right angled triangle.

Proof:

This can be proved easily.

Given that,

➡ ∠A = ∠B + ∠C

We know that,

Sum of interior angles in a triangle is 180°.

Therefore,

➡ ∠A + ∠B + ∠C = 180°

Now, substitute the value of ∠A here.

We get,

➡ ∠B + ∠C + ∠B + ∠C = 180°

➡ 2(∠B + ∠C) = 180°

➡ ∠B + ∠C = 90°

Therefore,

➡ ∠A = ∠B + ∠C

➡ ∠A = 90°

Therefore, one of the interior angles of ΔABC is 90°

Therefore, ΔABC is a right angled triangle (Hence Proved)

Answer 2

Step-by-step explanation:

triangle ABC

LA= LB +LC

sum of angle of triangle=180°

LA + LB +LC=180°

(we know that in one triangle there's is Only one 90°)

so, LA=LB+LC

90°=45°+45°

90=90

(LB AND LC can be 30,60,45 or anything,so by adding we can get 90)

hence proved