The answer is C. Square root of 29
These two triangles are congruent so we just have to figure out the length of two sides then use the Pythagorean theorem to solve for the last side
Pythagorean theorem:
a^2 + b^2 = c^2
We know one of the legs is 5 so:
5^2 + b^2 = c^2
25 + b^2 = c^2
The base of the triangle is 4 but since the line in the middle is a perpendicular bisector to the base, both sides of the line are equal to 2
So now we know the value of the other leg:
25 + 2^2 = c^2
25 + 4 = c^2
29 = c^2
Now you take the square root of both sides
Square root of 29 = c
~~hope this helps~~