Answer:
HL = 21
Step-by-step explanation:
HL is the midsegment of the trapezoid shown above. Thus, it follows that:
HL = (JK + GF)/2
JK = 12
GF = 2.5(JK) = 2.5(12) = 30
Plug in the values:
HL = (12 + 30)/2
HL = 42/2
