How to factorize the square of 28 + 56 * 42 + 4

How to factorize the square of 28 + 56 * 42 + 4

28 square meters + 56 * 42 + 42 square meters
=28 square + 2 * 28 * 42 + 42 square
=(28+42)²
=70²
=4900