1) Examining that rectangular picture, we can write out its Perimeter (2P) as the sum of its sides.
2) Since a rectangle has two pairs of parallel and congruent sides we can write out:
2P = 2a -2b + 2a -2b + 5a +3b +5a +3b Combine like terms
2P = 4a + 10a + 6b - 4b
2P = 14a +2b
3) Hence, the Perimeter (2P) of this rectangular frame is 14a + 2b
