Use the Pythagorean theorem to find the length of AC. Enter the answer in simplified form.
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Answer :
=> (AB)² + (AC)² = (BC) ²
=> (AC)² = (BC)² - (AB)²
=> (AC)² = (4√5)² - (2√5)²
=> (AC)² = 80 - 20
=> (AC)² = 60
=> AC = √60
=> AC = 2√15