I don't understand this.. and i need help asap

Geometry: determine whether segment mn is parallel to segment kl. justify your answer. jm 6 mk 3 jn 8 nl 4

In δabc, m∠acb = 90°, cd ⊥ ab and m∠acd = 45°. find: a find cd, if bc = 3 in

Isaac wants the equation below to have no solution when the missing number is placed in the box. which number should he place in the box?