We know that , According to Pythagorean Theorem :
In a Right Angled Triangle :
✿ (Hypotenuse)² = (First Leg)² + (Second Leg)²
In the Figure : AC is the Hypotenuse and AB and BC are Two Legs
Given : Length of AB = 4 and Length of BC = 6
⇒ (AC)² = (AB)² + (BC)²
⇒ (AC)² = 4² + 6²
⇒ (AC)² = 16 + 36
⇒ (AC)² = 52
![\mathsf{\implies AC = √(52)}](https://img.qammunity.org/2019/formulas/mathematics/college/so913knaj97qzkav883eqeqhw6lkti4to4.png)
![\mathsf{\implies AC = 2√(13)}](https://img.qammunity.org/2019/formulas/mathematics/college/khbsecj0qal7pbujw5kxrbjupsm2grk4zj.png)
3rd Option is the Answer