Question

how can i draw a triangle so some one can answer my problem

Answer 1

now that you have posted add a comment using the draw button at the bottom of the box there

Answer 2

what are the missing side lenghts in the given 45-45-90 angle?

Answer 3

45-45-90 means that the two sides are equal...ya?

a^2 + b^2 = c^2 and in this case a^2 = b^2 so that really is a^2 + a^2 = c^2 also known as

2(a^2) = c^2 and since c = 12 that should not be too hard