This is a 45°-45°-90° triangle, in which the sides occur in a ratio of 1 to 1 to √2. So <em>x</em> = √2.
If you didn't already know that, you can trigonometry. By definition of cosine,
cos(45°) = 1/<em>x</em>
Then
<em>x</em> = 1/cos(45°) = 1/(1/√2)) = √2
Answer:
d
Step-by-step explanation:
the answer is true........