Video Transcript
An irregular object is measured
with a ruler to find its maximum length. Which of the following best shows
how to use a ruler to take this measurement? Is it (A), (B), (C), or (D)?
Here in this question, we’re given
an irregular object that we want to measure the length of. We are shown four different options
of where we can place our ruler to get a measurement and are asked to figure out
which option is the best way to measure this object with it.
First, we should remember some
information about rulers and how to take accurate measurements with them. Rulers are made from a straight
strip of material and are marked along its length at different measurements. Rulers always begin at zero and
increase in value as you move to the end of it. When measuring a length, the zero
mark of the ruler must be placed in line with the end of the length. We also have to set the ruler
parallel to the object we are measuring in order to get the accurate length of
it.
Take a look at the irregular object
we are trying to measure. It looks like a rectangle with two
corners cut off at an angle. So the top length and the bottom
length, the blue line, are the same length but are not the entire length of our
object. Notice that the center of our
object, the red line, actually has the longest length. We should do our measurements along
the centerline of our object, so we can already eliminate the first two options from
being correct, because the ruler is lying along the top edge and bottom edge in
them.
Looking at the two options that are
measuring the center of our object, one of them has the ruler in front of the object
and the other is behind the object. In order to properly measure the
length of the object, we would obviously need to see the markings on the ruler, so
we should always put the ruler in a position where we can read the measurements
along it.
Therefore, option (C), measuring
the object along the centerline with the ruler on top of the object is the correct
answer.
