Please help with this question asap

Pythagoras theorem: leg 1 squared + leg 2 squared = hypotenuse squared

In the diagram, the triangle has angles 90 and 45. So the other angle in the triangle must be 45 degrees as well.  (180 - 90 -45 = 45)

This means it is an isosceles triangle (since two angles are the same), so the two legs have the same length.

So we can say that length of leg1 = x, and the length of leg2 also equals x

Now let's use pythagoras' theorem:

leg1 = x

leg2 = x

hypotenuse = 16

x^2 + x^2 = 16^2

      2x^2 = 16^2

      2x^2  = 256

        x^2 = 128

        x = √(128)

        x = 8√2

b is the correct answer