The rhombus below NL=3, KL=5, and angle JML=60°Find angle KLM

A rhombus has certain characteristics that will be of use in this problem:
• All interior angles add up to 360.
,• Opposite angles are congruent.
Based on the latter, we can build the following conclusions:
[tex]m\angle JLM=m\angle JKL[/tex][tex]m\angle KLM=m\angle KJM[/tex][tex]m\angle JLM+m\angle JKL+m\angle KLM+m\angle KJM=360[/tex]As m∠JLM is given, and as opposite angles measure the same, we can do the following:
[tex]2\cdot(m\angle JLM)+2\cdot(m\angle KLM)=360[/tex][tex]2\cdot(60)+2\cdot(m\angle KLM)=360[/tex][tex]120+2\cdot(m\angle KLM)=360[/tex]Solving for m∠KLM:
[tex]2\cdot(m\angle KLM)=360-120[/tex][tex]2\cdot(m\angle KLM)=240[/tex][tex]m\angle KLM=\frac{240}{2}[/tex][tex]m\angle KLM=120[/tex]Answer: a. 120