Can a triangle have
    (i) Two right angles?
    (ii) Two obtuse angles?
    (iii) Two acute angles
    (iv) All angles more than 60° ?
    (v) All angles less than 60° ?
    (vi) All angles equal to 60° ?

(i) A triangle cannot have two right angles as the sum of the three angles of a triangle is 180°.
If two angles are right angles then their sum will be 180° which contradicts the above
statement.
∴ A triangle cannot have two right angles.
(ii) If two angles are obtuse angles then their sum will be > 180°. But sum of three angles of
a triangle is 180°.
∴ A triangle cannot have two obtuse angles.
(iii) If two angles are acute angles then their sum will be <180^o. Since sum of three angles of a triangle is 180° .
∴ A triangle can have two acute angles.
(iv) If all angles are > 60° then sum of three angles will be > 3 × 60° = 180^o .Since sum of three angles of a triangle is 180°.
∴ All angles cannot be more than 60°.
(v) If all the angles are < 60° then sum of three angles will be < 3 × 60° = 180^o.Since sum of three angles of a triangle is 180°.
∴ All angles cannot be less than 60°. (vi) If each angle = 60° then sum of three angles will be = 3 × 60° = 180°.
Since sum of three angles of a triangle is 180°.∴ All angles can be equal to 60°.