Answer:
a
Step-by-step explanation:
For this question we need to use the Pythogorean Theorem as we know its a right angle and are missing a side.
The Pythogorean Theorem is [tex]a^{2} + b^{2} = c^{2}[/tex], where a and b are any side other than the hypothenuse, the longest line, and c is the hypothenue.
So, plug in the values and you get [tex]7^{2} + 2^{2} = x^{2}[/tex]
[tex]7^{2} + 2^{2} = 4 + 49 = 53[/tex]
So now we just find the square root, which as it isn't a square number we can just leave it as it is, as a surd, so the answer is 'a'.
