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

1.	In an isosceles triangle, one angle is 70°. The other two angles are of(i) 55° and 55° (ii) 70° and 40° (iii) any measureIn the given option(s) which of the above statement(s) are true?(a) (i) only (b) (ii) only (c) (iii) only (d) (i) and(ii)
Answer» (d) (i) and (ii) From the question it is given that, One angle of isosceles triangle is 70^o. We know that, in an isosceles triangle 2 angles are equal corresponding with 2 equal sides, If 70^o is 3^rd angle of triangle, 70^o + x + x = 180^o 2x + 70^o = 180^o 2x = 180^o – 70^o x = (110^o/2) x = 55^o So, both angles are 55^o Consider the 70^o as base angle of isosceles triangle Then, 70^o + 70^o + x = 180^o x = 180^o – 140^o x = 40^o So, one angle is 40^o and another is 70^o

In an isosceles triangle, one angle is 70°. The other two angles are of(i) 55° and 55° (ii) 70° and 40° (iii) any measureIn the given option(s) which of the above statement(s) are true?(a) (i) only (b) (ii) only (c) (iii) only (d) (i) and(ii)

Answer»

(d) (i) and (ii)

From the question it is given that,

One angle of isosceles triangle is 70^o.

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

If 70^o is 3^rd angle of triangle,

70^o + x + x = 180^o

2x + 70^o = 180^o

2x = 180^o – 70^o

x = (110^o/2)

x = 55^o

So, both angles are 55^o

Consider the 70^o as base angle of isosceles triangle

Then, 70^o + 70^o + x = 180^o

x = 180^o – 140^o

x = 40^o

So, one angle is 40^o and another is 70^o