5.5 Parallel Lines (Sample Questions)


Example 1:

















The straight lines MN and PQ in the diagram above are parallel. Find the value of q.

Solution:
If two lines are parallel, their gradients are equal.
m1 = m2
mMN = mPQ

using gradient formula y 2 y 1 x 2 x 1 9 4 5 ( 1 ) = q ( 5 ) 5 ( 7 ) 5 6 = q + 5 12
60 = 6q + 30
6q = 30
q = 5