Lesson 9
Drawing Triangles (Part 1)
Let’s see how many different triangles we can draw with certain measurements.
Problem 1
Use a protractor to try to draw each triangle. Which of these three triangles is impossible to draw?
 A triangle where one angle measures \(20^\circ\) and another angle measures \(45^\circ\)
 A triangle where one angle measures \(120^\circ\) and another angle measures \(50^\circ\)

A triangle where one angle measures \(90^\circ\) and another angle measures \(100^\circ\)
Problem 2
A triangle has an angle measuring \(90^\circ\), an angle measuring \(20^\circ\), and a side that is 6 units long. The 6unit side is in between the \(90^\circ\) and \(20^\circ\) angles.
 Sketch this triangle and label your sketch with the given measures.
 How many unique triangles can you draw like this?
Problem 3
 Find a value for \(x\) that makes \(\textx\) less than \(2x\).
 Find a value for \(x\) that makes \(\textx\) greater than \(2x\).
Problem 4
One of the particles in atoms is called an electron. It has a charge of 1. Another particle in atoms is a proton. It has charge of +1.
The overall charge of an atom is the sum of the charges of the electrons and the protons. Here is a list of common elements.
charge from electrons 
charge from protons 
overall charge 


carbon  6  +6  0 
aluminum  10  +13  
phosphide  18  +15  
iodide  54  +53  
tin  50  +50 
Find the overall charge for the rest of the atoms on the list.
Problem 5
A factory produces 3 bottles of sparkling water for every 7 bottles of plain water. If those are the only two products they produce, what percentage of their production is sparkling water? What percentage is plain?