Cdkm is a parallelogram, da ⊥ ck , dk – cd = 7 ca = 6, ak = 15 find: cd and dk

We have this parallelogram shown in the picture (just ignore the letters). Let's  DK (in the picture it is AC) with x and CD (in the picture it is AD) with x-7. Applying Pythagoras theorem, we can write that DA (in the problem, in the picture it is AE) is . Solving this equation, we find the value of x and it is 106/7. That's the value of DK. And CD=106/7-7=57/7

The answers are 20,30,80,180,960,890,1230,4560. on the first row