Which one of the following proportions is true for the segments shown in the figure if lines a, b, and c are parallel to each other?

Solution :

As given in the figure

a ║ b ║ c

∠1= ∠ 5,

∠2 = ∠6

∠3=∠7

∠4 =∠8

As all these angles are corresponding angles.

So Trapezoid ABCD and Trapezoid CDEF are similar.

When two polygons are similar their sides are proportional.

the entire expression should be subtracted from 30. to subtract the quantity, distribute the negative sign, which changes the signs on the terms. so, the –2 changes to positive and gets added to 30 instead of subtracted from it.

hope this ! ^w^