### Home > GC > Chapter 3 > Lesson 3.1.2 > Problem 3-21

3-21.

Read the following statements and decide if, when combined, they present a *convincing* argument. You may need to refer back to your Shape Toolkit as you consider the following statements and decide if the conclusion is correct. Be sure to **justify** your reasoning.

**Fact #1: **A square has four sides of equal length.

**Fact #2: **A square is a rectangle because it has four right angles.

**Fact #3: **A rhombus also has four sides of equal length.

**Conclusion: **Therefore, a rhombus is a rectangle.

Consider whether or not a rhombus has