1)
PQ/PR = JK/JL
PQ/21 = 12/14
PQ = 12 * 21 / 14
PQ = 18
2)
a)
If two pairs of corresponding angles in a pair of triangles are congruent, then the triangles are similar.
So yes, The plots are similar
b)
x / 6180 = 7436 / 8240
x = 6180*7436 / 8240
x = 5577