Answer:
A
Explanation:
This is a right triangle, because of the little square in the corner that represents a right angle.
Therefore, the Pythagorean Theorem can be used.
a^2+b^2=c^2
where a and b are the legs, and c is the hypotenuse
In this triangle, 2 and 10 are the legs, because they form the right angle. x is the hypotenuse, because it is opposite the right angle.
2 and 10 are a and b, and x is c.
2^2+10^2=x^2
Evaluate the exponents on the left side.
4+100=x^2
104=x^2
x is being squared. To reverse this, take the square root of both sides
√104=√x^2
√104=x
A, x=√104 is correct