Question

In a triangle, an exterior angle at a vertex is 95° and its one of the interior opposite angle is 55°, then the measure of the other interior angle is

Options

•  55°

•  85°

•  40°

•  9.0°

Answer 1

In the given ΔABC, ∠DAC = 95° and ∠A = 55°

Now, according to the property, “exterior angle of a triangle is equal to the sum of two opposite interior angles”, we get,

∠A + ∠B = ∠ACD

55° + ∠B = 95°

        ∠B = 95° - 55°

              = 40°

So, ∠B = 40°