Is an isosceles triangle the base angles are equal the vertex angle is 40 What are the base angles of the triangle?

Last updated at May 24, 2022 by

Solve all your doubts with Teachoo Black (new monthly pack available now!)

Ex 4.4, 2 (b) In an isosceles triangle, the base angles are equal. The vertex angle is 40°. What are the base angles of the triangle? (Remember, the sum of three angles of a triangle is 180°). Let, base angles be of = b° Given that, Vertex angle = 40° Now, we know that, Sum of all angles of a triangles = 180° So, 40 + b + b = 180 40 + 2b = 180 2b = 180 − 40 2b = 140 b = 140/2 b = 70 ∴ Base angles of given isosceles triangle is 70°

Solve the following:

In an isosceles triangle, the base angles are equal. The vertex angle is 40°. What are the base angles of the triangle? (Remember, the sum of three angles of a triangle is 180°).

Let the base angles be equal to b.

The sum of all interior angles of a triangle is 180°.

b + b + 40° = 180°

2b + 40° = 180°

2b = 180º - 40º = 140º (Transposing 40º to R.H.S.)

Dividing both sides by 2,

`(2b)/2 = 140^@/2`

b = `70^@`

Therefore, the base angles of the triangle are of 70º measure.

Concept: Applications of Simple Equations to Practical Situations

Is there an error in this question or solution?

Uh-Oh! That’s all you get for now.