Iven: klmn is a trapezoid m∠k = 90°, m∠n = 45° lk = lm = 10 find: kn, area of klmn

We have a right trapezoid since ∠K=90°. We know that KL=LM, then the triangle KLM is an isosceles and according to the Pythagoras theorem KM = 10√2. 

The sum of all quadrilaterals is 360° and using this fact we can say that ∠LMN=135° and since we know that ΔKLM is an isosceles( ∠LMK=45°), ∠KMN=90° and since ∠MNK=45°, then ∠MKN=45°. It means triangle KMN is a right-isosceles triangle and KM=MN=10√2. According to Pythagoras theorem KN=20

And the area of the trapezoid is 

1. isolate the variable, in this case, d. subtract 35.5 on both sides of the equation.2. 52 subtracted by 35.5 is 16.53. therefore your answer would be d= 16.5this is the basics of pre algebra, isolating variable through adding, subtracting, multiplying, and dividing, if you have any other questions to ask just comment!