Question

In an isosceles ∆ ABC  base equal angle is 6 degree   more than vertex angle find each angle​

Answer 1

Answer:

Let the base angles be x

Therefore,

x+x+40 °

=180 °

2x=180 °

−40 °

2x=140 °

x=70 °

Hence,

The base angles of the triangle are 70 °

,70 °

Answer 2

In an Isosceles triangle the two base angles are congruent. The third angle is the vertex angle. In any triangle the sum of the three angles will be 180°.

Let v = the vertex angle

let b = each of the base angles

v + b + b = 180°

v = b + 9 (The vertex angle of an isosceles triangle is 9 degrees more than a base angle)

Substitute b + 9 for v, in the equation v + b + b = 180°

(b + 9) + b + b = 180° combine like terms to simplify

3b + 9 = 180° Subtract 9 from both sides

3b = 171° Divide both sides by 3

b = 57°

v = b + 9° => v = 57° + 9° = 66°

Check: 57° + 57° + 66° = 180°