Similar and congruent figures

Learning Objectives Define and identify congruent figures. Define and identify similar figures. Distinguish between similar and congruent figures. Identify corresponding parts of similar and congruent figures. Calculate the scale factor between two similar figures. Use proportions to find unknown side lengths in similar figures. Have you ever wondered why all the bricks in a wall look exactly the same, or why a miniature model car looks just like the real thing, only smaller? 🤔 In this lesson, you'll explore the fascinating world of similar and congruent figures. You'll learn how to identify shapes that are identical in size and shape, and shapes that have the same shape but different sizes. Understanding these concepts is fundamental to geometry and helps us des...

TermDefinitionExample Figure/ShapeA general term for any two-dimensional or three-dimensional geometric form.A square, a triangle, a circle, or a cube are all figures. Congruent FiguresFigures that have the exact same size and the exact same shape. They can be perfectly superimposed on each other.Two identical square tiles, or two copies of the same photograph printed at the same size. Corresponding PartsThe matching angles and sides of two or more figures. If you were to place one figure exactly on top of the other, the corresponding parts would line up.In two congruent triangles, the longest side of one triangle corresponds to the longest side of the other triangle. Similar FiguresFigures that have the same shape but not necessarily the same size. Their corresponding angles are equal, a...

Rule for Congruent Figures If two figures are congruent, then all their corresponding angles are equal, and all their corresponding sides are equal in length. Use this rule to determine if two figures are identical in every way, or to find missing measurements in figures known to be congruent. Rule for Similar Figures (Angles) If two figures are similar, then all their corresponding angles are equal. This is the first condition to check when determining if two figures are similar. If corresponding angles are not equal, the figures cannot be similar. Rule for Similar Figures (Sides/Proportions) If two figures are similar, then the ratios of the lengths of their corresponding sides are equal. This constant ratio is called the scale factor. $\frac{\text{Side 1 of Figure...