Triangle JKL is isosceles. The measure of angle J is 72 degrees and the measure of angle K is 36 degrees.

Step-by-step explanation:

"which is the measure of angle L?"

the total angle measures of all angles on a triangle should always equal 180

72 + 36 = 108

180 - 108 = 72!

angle L is 72 degrees!

"which angle is the vertex angle?"

from my understanding, the angle opposite the base would be the vertex angle

since j and k are equal, we can only assume 36 is the vertex angle!

hope this helps! if so, pls give brainliest!

hi. I'm so sorry I just need to answer some questions. I'm sorry

not only in mathematics, scientific proof also are required in the other field of science. also maths proofs are of particular structure, containing steps and logics. so proving is like doing science, it is science. that's why it is important to prove. 

an inaccurate proof leads to errors, or stating results that are not accurate.  which wil mess the probelm up you dont want this