
We are given that the diameter = 42 millimeters

The circumference of the lid is approximately
131.95 millimeters.
Line 2: You should have added 7 to both sides.
Answer:
The letter "b" indicates it is effective against flammable liquid fires.
Step-by-step explanation:
The letters on fire extinguishers represents the class of fire for which they can be used.
The letter "b" here indicate the b-1 extinguisher is effective against flammable liquid fires. These can be fires where cooking liquid , oil , gasoline , kerosene or paint.
The length of the midsegment of an isosceles trapezoid is the sum of the two bases, divided by 2. So this means -
(base 1+base2) / 2
(12+20) / 2
32/2
Length of midsegment = 16
Is there suppose to be a link or something more to this question?