In a Right Angled Triangle : The Sum of Squares of Two other sides which are not Hypotenuse should be Equal to Square of the Hypotenuse.
Now let us Check the Options :
Option A : √4 , 10 , 116
⇒ 4 + 10² = 116²
⇒ 4 + 100 = 116²
⇒ 104 ≠ 116²
This is not a Right Angled Triangle
Option B : 3 , 6 , 8
⇒ 3² + 6² = 8²
⇒ 9 + 36 = 64
⇒ 45 ≠ 64
This is not a Right Angled Triangle
Option C : 30 , 40 , 50
⇒ 30² + 40² = 50²
⇒ 900 + 1600 = 2500
⇒ 2500 = 2500
In the Given Options : Only Option C satisfies this Condition
Option C is the Answer