Answer:
48
Step-by-step explanation:
Reason number 1 (before) is that you could contaminate your samples if you have foreign material on your hands.
Reason number 2 (after) is that you could spread<span>/or ingest dangerous chemicals or substances that you have handled in the lab.</span>
The lines are parallel bc if you change -10x+y=4 into y=10x+4 they will have the same slope of m=10x
ADC = 40 + 30 = 70 degrees
DBC is given at 45 deg
AEB = 100 degrees, vertical angle from intersecting lines
BCD = 50 + 50 = 100 degrees