The words why'd, wide sound the same but have different meanings and spellings. Why do why'd, wide sound the same even though they are completely different words?
The answer is simple: why'd, wide are homophones of the English language.
Shortened form of why did.
Shortened form of why had.
Shortened form of why would.
Having a specified extent from side to side: a ribbon two inches wide.
Extending over a great distance from side to side; broad: a wide road; a wide necktie.
Having great extent or range; including much or many: a wide selection; granting wide powers; wide variations.
Fully open or extended: look with wide eyes.
Definitions from Wiktionary, Creative Commons Attribution/Share-Alike License, from The American Heritage® Dictionary of the English Language, 4th Edition and Wordnik.
Homophones (literally "same sound") are usually defined as words that share the same pronunciation, regardless of how they are spelled.