Answer:
45
Step-by-step explanation:
∡L ≅ ∡M, given
ΔKLM is isosceles because base angles are congruent
KM ≅ KL and KM = KL
KL = 12
∡K =∡J = 60°, given
∡M = 180 -60 -60 , because sum of angles in a Δ is equal to 180°
∡M = 60
∡K =∡J =∡M = 60°
ΔKJM is is equilateral because all angles have the same measure.
KM = 12
KM = KJ = JM = 12 because the triangle is equilateral so all sides are equal
ML = 9, given
The perimeter of JKLM is the sum of the sides
P = ML +KL +KJ +MJ
P = 9 + 12 + 12 +12 = 9 +36 = 45
