Need help pls
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under square root of 50 ()

Step-by-step explanation:

Use pythagorean theorem. a^2 + b^2 = c^2. 5^2 is one leg, the other leg is also 5^2, and the x is what we need. So 5^2 is 25. 25 + 25 is 50. Thus, x is  (or under square root of 50), which is our answer!

check the picture below.

well, the angle at the vertex d is clearly not a right-angle, let's check for the one at the vertex f which does look like,   however if it's indeed, that means ef is perpendicular to df, in which case their slopes will be negative reciprocal of each other.

so the negative reciprocal of the slope of ef is 1, however the slope of df is not 1, is 1/2, so nope, they're not perpendicular lines.