You can solve this by finding all of the factors of 28 and seeing which ones add up to 22 when doubled.
The factors of 28 are as follows:
28 x 1 28(2) + 1(2) = 56 + 2 = 58 ≠ 22
14 x 2 14(2) + 2(2) = 28 + 4 = 32 ≠ 22
7 x 4 7(2) + 4(2) = 14 + 8 = 22
The dimensions of the rectangle are 4 x 7.
