Question

JKL is an equilateral triangle and KM and JL

Answer 1

Line KM bisects the equilateral triangle, which halves Angle K. 

Because all angles of an equilateral triangle are 60, we can divide the original angle of K by 2 to find the new angle:

$60 \div 2 = 30$

Angle K is 30 degrees.

Triangle JKM has two angles of 90 and 30. Angle M is 90 degrees, as it has the square defining the angle, and Angle K is 30 degrees. Angle J has remained unchanged, so it is 60 degrees. This makes Triangle JKM a 30-60-90 triangle.

The answer is B.