Consider the following statements: When two straight lines intersect:
(i)adjacent angles are complementary
(ii)adjacent angles are supplementary
(iii)opposite angles are equal
(iv)opposite angles are supplementary
Of those statements
(a) (i) and (iii) are correct 
(b)  (ii) and (iii) are correct
(c) (i) and (iv) are correct 
(d)  (ii) and (iv) are correct

Explanation

Now, let us consider each statement one by one:
(i) When two lines intersect adjacent angles are complementary. This statement is incorrect.
Explanation: The adjacent angles form a linear pair and are supplementary.

(ii) When two lines intersect adjacent angles are supplementary. This statement is correct.
Explanation: The adjacent angles form a linear pair and are supplementary.

(iii) When two lines intersect opposite angles are equal. This statement is correct.
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