Question

The inner isosceles of the angles of a triangle are three isosceles.

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Answer 1

Step-by-step explanation:

We first draw a bisector of ∠ACB and name it as CD. Hence proved. Theorem 2: Sides opposite to the equal angles of a triangle are equal. Proof: In a triangle ABC, base angles are equal and we need to prove that AC = BC or ∆ABC is an isosceles triangle.

explanation :

We first draw a bisector of ∠ACB and name it as CD.

Now in ∆ACD and ∆BCD we have,

AC = BC (Given)

∠ACD = ∠BCD (By construction)

CD = CD (Common to both)

Thus, ∆ACD ≅∆BCD (By SAS congruence criterion)

So, ∠CAB = ∠CBA (By CPCT)

Hence proved.

Answer 2

Answer:

x=70 is the right answer please mark me as branliest

Step-by-step explanation:

Let x be the base angle of an isosceles triangle.

It is given that the base angles of an isosceles triangle are equal and the vertex angle of an isosceles triangle is 400 .

We know that the sum of three angles of a triangle is 180 degrees.

x + x + 40 = 180

2x + 40 = 180

2x = 180-40

2x = 140

Dividing both sides by 2, we get

x = 70.

Hence the base angle of an isosceles triangle is 70 degree.

Both the base angles are equal; the second base angle of the isosceles triangle is also 70 degree.

Therefore, the base angles of the isosceles triangle are 700,700.

Note: In an isosceles triangle the base angles are equal and the vertex angle is 40 degree then base angles are 1402=70 degree each. The name isosceles derives from the Greek iso (same) and skelos (leg).