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?

  1. A triangle where one angle measures \(20^\circ\) and another angle measures \(45^\circ\)
  2. A triangle where one angle measures \(120^\circ\) and another angle measures \(50^\circ\)
  3. 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 6-unit side is in between the \(90^\circ\) and \(20^\circ\) angles.

  1. Sketch this triangle and label your sketch with the given measures.
  2. How many unique triangles can you draw like this?

Problem 3

  1. Find a value for \(x\) that makes \(\text-x\) less than \(2x\).
  2. Find a value for \(x\) that makes \(\text-x\) greater than \(2x\).
(From Unit 5, Lesson 13.)

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.

(From Unit 5, Lesson 3.)

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?

(From Unit 4, Lesson 3.)