Question -
Answer -
It is given that AB || CDand CD || EF
∴ AB || CD || EF (Lines parallel to the sameline are parallel to each other)
It can beobserved that
x = z (Alternateinterior angles) … (1)
It isgiven that y: z = 3: 7
Let thecommon ratio between y and z be a.
∴ y =3a and z =7a
Also, x + y =180º (Co-interior angles on the same side of the transversal)
z + y = 180º [Usingequation (1)]
7a + 3a =180º
10a = 180º
a = 18º
∴ x =7a = 7 × 18º = 126º