In parallelogram ABCD, A(2,3), B(6,5) and D(4,7). Then the coordinates of C is
(8,9)
Draw AE, DF parallel to x-axis.
Draw BE, CF parallel to y-axis.
Now, in right triangles △ABE and △DCF,
AB = DC
∠BAE=∠CDF
∠ABE=∠DCF
Therefore, AE = DF and BE = CF
Hence,
AE = DF = 6 -2 = 4 and BE = CF = 5 - 3 = 2
Now,
x-coordinate of C = 4 + DF = 4 + 4 = 8
y-coordinate of C = 7 + CF = 7 + 2 = 9
Therefore coordinates of C(8,9)