The purpose of this Instructable is to help students distinguish between Acute, Obtuse, Right & Straight Angles by playing a variation of Rock, Paper & Scissors. Your students will love it!

## Step 1: Mathematical Note About Rock, Paper & Scissors

Note: Most rock, paper, scissor games are played with an odd number of choices in order to optimize game play. This insures that each move (rock, paper or scissors) has the same probability of winning. I choose to use four choices obtuse, acute, right and straight because they are the most common classification of angles that students must learn. Using an even number of choices creates some uneven outcomes and alters the strategy of game play, but this can be overlooked since the ultimate goal is for students to learn the concepts as opposed to being the winner

## Step 2: How the Game Works

The game-play is similar to Rock, Paper & Scissors except the hand gestures have changed. We will detail the hand gestures in the upcoming steps but this step details how rock, paper & scissors is played.

****Note: If you are familiar with how to play rock, paper & scissors, feel free to skip this step**

How to play Rock Paper & Scissors?

Taken from e-how

http://www.ehow.com/how_2051016_play-rock-paper-scissors.html

## Step 3: Obtuse Angle Hand Gesture

Here is the hand gesture for Obtuse angles

Obtuse x > 90 degrees

## Step 4: Acute Angle Hand Gesture

Here is the hand gesture for Abtuse angles

Acute Angle x < 90 degrees

## Step 5: Straight Angle Hand Gesture

Here is the hand gesture for Straight angles

Straight Angle (line) 180 degrees

## Step 6: Right Angle Hand Gesture

Here is the hand gesture for Right angles

Right Angle 90 degrees

## Step 7: Rules of Actual Game Play

*As stated in a previous step, since the choices of inputs are even (not odd), the distribution of outcomes will be not be evenly distributed. This can be overlooked since the ultimate goal is for students to learn to distinguish concepts as opposed to being the winner of the game.*

The distribution of outcomes are as follows

1) Obtuse Angles beat Acute Angles

2) Acute Angles beat Right and Straight Angles

3) Right Angles beat Obtuse Angles

4) Straight Angles beat Obtuse and Right Angles.

Here are pictures for my reasoning. Yes, my mind works like a child!

## Step 8: More From Hands on Math?

Visit our website http://handsonmath.blogspot.com/

or Goolge "Hands On Math, Jeremiah Dyke"

## 5 Discussions

6 years ago on Introduction

I like using hands to represent the different angles. I understand that you can't have an option that beats all the other options. However what is your reasoning for choosing the acute angle to beat the right and obtuse angles? This is counterintuitive to me, especially when I'm trying to teach that an obtuse angle is greater in degrees than a right angle and an acute angle.

Reply 6 years ago on Introduction

My reasoning is somewhat arbitrary so feel free to switch them around if it better fits your specific teaching style. I wouldn't base the outcomes on highest degree of angle though. If you did, everyone's strategy would be a straight angle each time. Any deviation from it would loose. Thus, you really wouldn't have a game. Hope this helps :)

6 years ago on Introduction

I got confused. It is the rule #4 that a straight angle beats obtuse and right angles that is counterintuve.

6 years ago on Introduction

What a cool idea!

6 years ago on Introduction

I think that this is a great way to remember angles! I love the simple math games that help to remember these, you learn so many of these in one go they do get a bit jumbled unless you are on the same subject for a while.

It does make it easy for projects where multiple angle situations can occur and I will most likely use it when I am programming movements or some rocket physics out on the oval.