Water Tower

3 Act Math

Act 1

1. How tall is the light pole?
2. Write down a guess.

All credit goes to my amazing wife for this lesson! She came up with the idea after noticing new lights by the water tower in our community.

Act 2

3. What information would be useful to figure this out?
4. Write down some questions you have in your head right now.


Act 3


5. If the light pole was 15 feet tall, how far away from the tower would it need to be? Assume the angle of elevation is still 42.7°.

Common Core Standards
Use trigonometric ratios and the Pythagorean Theorem to solve right triangles in applied problems.
determine the lengths of sides and measures of angles in a right triangle by applying the trigonometric ratios sine, cosine, and tangent to solve problems


9 thoughts on “Water Tower

  1. Thank you! I may be wrong, but the act 2 diagram could possibly be made more accurate. The length 130ft should go up to the sign only, instead of up to the top of the tower like you have done. With this diagram, there would be that extra bit to take off as well between the sign and the top of the tower. Do you agree?

      1. That’s perfect! Thanks heaps! This is a great resource that I will use for my teaching practical in a weeks time 🙂

      2. Great! Thanks for the help in making it better. Good luck next week, and let me know how it goes. I’m interested in seeing how the students approach it. Could you possibly gather some student work samples? I won’t get to use this lesson until next year, so I’m curious.

  2. I just did this task as my first ever 3-act math task yesterday! It went super well, and my students seemed to like it and were very engaged. I’m planning to do a lot more of these!! Thank you so much!!

  3. Hello, Dane! My Honors Geometry Class and I are trying to figure out the answer to the sequel! We’re having a little trouble. Would you mind providing the answer so we can check our work? Thanks! 🙂

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