Question

In an isosceles triangle, one angle is 70°. The other two angles are of ______.

1. 55° and 55°
2. 70° and 40°
3. any measure

In the given option(s) which of the above statement(s) are true?

Options

• (i) only

• (ii) only

• (iii) only

• (i) and (ii)

Answer 1

(i) and (ii)

Explanation:

From the question, it is given that,

One angle of an isosceles triangle is 70^o.

We know that, in an isosceles triangle 2 angles are equal corresponding with 2 equal sides,

If 70° is 3^rd angle of triangle,

70° + x + x = 180^o

2x + 70° = 180^o

2x = 180° – 70^o

x = `110^circ/2`

x = 55°

So, both angles are 55°

Consider the 70° as base angle of an isosceles triangle

Then, 70° + 70° + x = 180°

x = 180° – 140°

x = 40°

So, one angle is 40° and another is 70°.