In an isosceles triangle, the angle between equal sides is 40°. The bisectors of the other two angles will intersect each other at an angle of:
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 110°.
the triangle is isosceles, the two base angles are equal. Let's denote each of these base angles as B and C.
B = C
The sum of all angles in a triangle is 180°. So:
⇒ A + B + C = 180°
Given A=40°:
⇒ 40° + B + B = 180
⇒ 2B =140°
⇒ B = 70°
Angle between the bisectors = 90° + A/2 = 90° + 40°/2 = 90° + 20° = 110°