Question

In the given figure, AB || CD and EF || GH. Find the relation between a and b.

• A. 2a + b = 180°
• B. a + b = 180°
• C. a - b = 180°
• D. a + 2b = 180°

Answer 1

The correct option is B a + b = 180°

Since, AB || CD and EF is a transversal.
∠EIB = ∠EJD [Corresponding angles]
∠EJD = b [Given: ∠EIB = b]

Since, EF || GH and CD is a transversal,
$\angle EJD+\angle CKG={180}^o$ [Co-interior angles are supplementary]

$\Rightarrow b+a={180}^o$ [Given: ∠CKG = a]
Hence, the required relation is $a+b={180}^o$