Question

in an isosceles triangle the base angle are equal the vertex angle is 40° what are the base angle of the triangle ? (remember the sum of three angle of a triangle is 180°)​

Answer 1

Answer :

The measure of the base angles of the triangle are 70° and 70°.

Step-by-step explanation :

To Find,

• The base angles of the isosceles triangle

Solution,

Given that,

• The base angles are equal.
• The vertex angle of the triangle is 40°

Therefore,

Let us assume the base angles as x and x

➭ x + x + 40 = 180° .... sum of three angles of a triangle is 180°

➭ x + x + 40 = 180

➭ 2x + 40 = 180

➭ 2x = 180 - 40

➭ 2x = 140

➭ x = 140 / 2

➭ x = 70 ★

Hence, the measure of the base angles are 70° and 70°.

Now, Verification

➭ x + x + 40 = 180, by putting the values,

➭ 70 + 70 + 40 = 180

➭ 110 + 70 = 180

➭ 180 = 180

L.H.S = R.H.S

Hence, Verified !