Angle Activity

Program Information

Series: NASA Connect
Program: Eyes Over Mars
Segment Number: 6 (Watch entire program)
Duration: 00:04:06
Year Produced: 2000

NASA Connect Segment involving students in a classroom activity that measures shadows and uses geometry to determine sizes of angles.

NASA CONNECT™ is a series of Emmy®-award-winning, math-focused programs. Each program supports the national math, science, and technology standards and has three components that include (1) a 30-minute television broadcast; (2) a companion educator's guide; and (3) an online activity that further explores topics presented in the broadcast. These programs establish a connection between the math, science, and technology concepts taught in the classroom to those same concepts used everyday by NASA researchers.

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There are other ways
that we survey the Earth
which Erastothenes
never dreamed of.

NASA scientists
use airplanes and satellites.

But what if you want to
survey other planets like Mars.

NASA scientists are doing
that right now, but first.

Let's head to Central
Middle School
in Charlotte Court House, Virginia.

There students are following
in the footsteps of

Hi, welcome to
Central Middle School
in Charlotte Court House, Virginia.

NASA Connect asked us to
show how did the stage activity
for the show.

In this lesson you
work in small groups
to take accurate measurements
of shadows using geometry
to determine the size of an angle.

Here are the materials you
will need for each group:
a straight stake of approximately
ninety one centimeters long, a
meter stick or tape measure, a
piece of string approximately
ninety one centimeters and a
rock or weight, a scientific
calculator, index card, compass,
copies of the student data chart
for each student.

Lets begin.

Divide the class in research
groups of three to five members.

Set your measurement
station by first placing the
gnomon perpendicular to the ground.

For your measurement to be accurate,
it's critical that the gnomon is vertical.

To check the vertical
position, tie the rock or weight
to the string and dangle it above
the ground in front of the gnomon.

Next, measure the height of the

Place an index card under
the station to mark
where the shadow is.

Take measurements every
two minutes beginning
at least ten minutes
before local noon,
which is the time that
the sun is highest in the sky.

This will most likely not be
noon as indicated on your
time measuring device.

Students should note that
when the sun is highest
in the sky the shadow
length is the shortest.

Since the edge of the shadow is
fuzzy and the shadow is moving
from east to west in the Northern
Hemisphere, be careful in deciding
where to place your mark.

Record your data on data chart one.

Now, back in your classroom,
locate the latitude and longitude
of your school location and
record it on data chart number one.

Identify your best shadow link.

This is the best shadow
link at local noon time.

Next, calculate the tangent
by dividing the length
of the shadow by the height of the

Locate this number or the
nearest rounded
number on the tangent table.

The measure of the tangent
can also be found by
the dividing the length of a shadow
by the height of an object
on the scientific calculator.

Record tangent on student data

Make a scale drawing of your
gnomon and shadow.

Complete the triangle
and measure the tangent
with the protector
to verify the calculations.

What's next Jennifer?

Let's analyze the
data by reviewing the results
of this activity and by responding
to the following questions?

Did the weather conditions affect
the results of this activity?

If so, how?

As the shadow lengthens over time,
how would the angle be affected?

If each group uses a
gnomon with a
different length,
how would that affect the
results of this activity?

For more activities like
this, check out our website

NASA Connect would like to
the special thanks to the mentors
from the AIAA Chapter at Howard
University in Washington DC.

We appreciate all your help
with the student activity.