# Classifying shapes

8 videos
3 skills
In this tutorial, we'll classify two-dimensional figures based on the presence or absence of parallel or perpendicular lines, or the presence or absence of angles of a specified size. We'll also learn about special triangles called "right triangles". Common Core Standard: 4.G.A.2

VIDEO 8:24 minutes
"Quad" means "four" and "lateral" means "line." A quadrilateral is literally a shape with four sides (lines) and four angles. Let's learn the difference between concave and convex quadrilaterals as well as trapezoids, parallelograms, and ...

VIDEO 5:07 minutes
How about this: we are given a 4-sided shape and asked to determine whether its properties qualify it to be called a quadrilateral (or category of quadrilaterals). Check it out.

### Quadrilaterals: kites as a geometric shape

VIDEO 5:38 minutes
Is a kite a quadrilateral? Is it a rhombus? A parallelogram? Let's find out.

### Quadrilaterals: find the type exercise

VIDEO 2:49 minutes
Take a look at the given data and determine what type of quadrilateral we have.

PRACTICE PROBLEMS
Identify quadrilaterals based on pictures or attributes.  Quadrilaterals included are parallelograms, rhombuses, rectangles, and squares.

### Triangles: categorization by angle or equal sides.

VIDEO 6:00 minutes
Scalene, isosceles, equilateral, acute, right, obtuse. All are types of triangles but what makes them special depends on the method of categorization. Watch this outstanding explanation.

### Triangles: using angles to categorize

VIDEO 5:30 minutes
You say you can't categorize a triangle because you don't know the length of the sides. Guess what? If you know the size of the angles you can!

### Categorizing triangles

VIDEO 2:23 minutes
Let's practice categorizing triangles in this example exercise.

### Recognizing triangle types

PRACTICE PROBLEMS
Identify triangles by their angles as acute, right, or obtuse.  Identify triangles by their side-lengths as equilateral, isosceles, or scalene.

### Categorizing geometric shapes: practice examples

VIDEO 2:15 minutes
Watch and do these example exercises along with us. Remember what you have learned about perpendicular lines, right, obtuse, and acute triangles.

### Classifying shapes by line and angle types

PRACTICE PROBLEMS
Classify shapes based on pictures or attributes, such as angle types and side-lengths.