one of the base angles of an isosceles triangle is 70 . the vertical angle is
Given : One of the base angle of an isosceles triangle is 70°
⇒ Other base angle of the isosceles triangle = 70°
Now, we know that the sum of the measure of all the angles of a triangle is 180°
⇒ One base angle + other base angle + vertical angle = 180°
⇒ 70° + 70° + vertical angle = 180°
⇒ 140° + vertical angle = 180°
⇒ vertical angle = 180° - 140° = 40°