pls help me answer this (multiple choice)

Answer:
Option 3, 18.0
Step-by-step explanation:
To find the Hypotenuse of a right triangle, use the Pythagoras theorem:
[tex]a^{2} +b^{2} =c^{2}[/tex]
(see image below)
(the longest side of any right △ is always C)
In this equation, we know A is 10 and B is 15, so plug in these numbers and solve for C
[tex]10^{2} +15^{2} =c^{2}[/tex]
[tex]100 + 225 =c^{2}[/tex]
[tex]325 = c^{2}[/tex]
Now that the equation is simplified, we find the square root of 325 to solve for C.
[tex]\sqrt{325 = c^{2}}[/tex]
[tex]18.0 = c[/tex]
The final answer is C = 18.0
Hope this helps you understand :)