About This Chapter
How It Works:
- Find the lesson within this chapter that corresponds to what you're studying in the Geometric Relationships chapter of your textbook.
- Watch fun videos that cover the geometric relationships concepts you need to learn or review.
- Complete the quiz after watching each video lesson to test your understanding.
- If you need additional help, rewatch the videos until you've mastered the material, or submit a question for one of our instructors.
You'll learn all of the math topics covered in the textbook chapter, including:
- Types of angles and angles formed by transversals
- Classifying lines as transverse, perpendicular or parallel
- Triangle exterior and interior angles
- Coordinate geometry and dilation in a coordinate plane
- Using midpoint and distance formulas
- Understanding quadrilaterals and polygons
- Proof of congruence in triangles
- Locating and graphing plane figures
Explorations in Core Math is a registered trademark of Houghton Mifflin Harcourt, which is not affiliated with Study.com.
1. Classifying Triangles by Angles and Sides
Not all triangles are the same. There are equilateral, isosceles and scalene triangles. Then there are right, acute and obtuse triangles. In this lesson, we'll learn how to classify triangles using their sides and angles.
2. Interior and Exterior Angles of Triangles: Definition & Examples
Knowing just a few things about the interior or exterior angles of triangles is sometimes all you need to put all the pieces together. Find out more in this lesson.
3. Angles and Triangles: Practice Problems
Want more practice solving with angle pairs? How about more review for solving angles in triangles? Look no further. Get more practice here, and test your ability with a quiz.
4. Dilation in a Coordinate Plane
This lesson illustrates a dilation in a coordinate plane, by demonstrating how to use the origin as the center of the dilation and the given scale factor to find the coordinates of the vertices of the image.
5. How to Use The Midpoint Formula
The formula for the midpoint of a line segment will tell you how to find the middle of any line segment on the x, y plane. Learn about this formula and see how it is used to find the midpoint of a line segment.
6. How to Use The Distance Formula
You can't always rely on your smartphone to tell you how far you need to travel to get from point A to point B. The distance formula will tell you the distance between any two points on a graph. In this lesson, you'll learn where it comes from and how to use it!
7. What is a Polygon? - Definition, Shapes & Angles
Polygons are everywhere! In this lesson, you will learn what they are and what they look like. You will also learn about a special class of polygons and how to find its angles.
8. What is a Quadrilateral? - Definition, Properties, Types & Examples
This lesson explains the definition and properties of a quadrilateral. We will look at examples of two categories of quadrilaterals. At the end, you will be able to test your knowledge with a quiz.
9. Congruence Proofs: Corresponding Parts of Congruent Triangles
Congruent triangles have congruent sides and angles, and the sides and angles of one triangle correspond to their twins in the other. In this lesson, we'll try practice with some geometric proofs based around this theorem.
10. Diameter and Circumference Related with Pi
After watching this video, you will be able to tell others how the number pi is related to a circle's diameter and circumference. And using your newfound knowledge, you will be able to calculate the circumference or diameter of a circle.
11. Circles: Area and Circumference
Understanding how to calculate the area and circumference of circles plays a vital role in some of our everyday functions. They serve as the foundation for operating with three-dimensional figures. Learn more about the area and circumference of circles in this lesson.
12. Combined Figures: Perimeter, Area, and Volume
Watch this video lesson to learn how you can break up the shapes in a combined figure to easily find the perimeter, area, and volume of the whole figure.
13. Prisms: Definition, Area & Volume
Watch this video lesson and you will see that there are different kinds of prisms. You will also learn how to separate a prism into its various parts so you can easily find the surface area. You will also learn the formula for the volume.
14. What Are Cylinders? - Definition, Area & Volume
Watch this video lesson to learn why soda cans are cylinders and the method by which you can discover how much soda can fit inside by finding the volume. You will also learn about finding a cylinder's surface area.
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Other chapters within the Explorations in Core Math - Grade 8: Online Textbook Help course
- Explorations in Core Math Grade 8 - Chapter 1: Rational Numbers
- Explorations in Core Math Grade 8 - Chapter 2: Graphs and Functions
- Explorations in Core Math Grade 8 - Chapter 3: Exponents & Roots
- Explorations in Core Math Grade 8 - Chapter 4: Ratios, Proportions & Similarities
- Explorations in Core Math Grade 8 - Chapter 6: Measurement and Geometry
- Explorations in Core Math Grade 8 - Chapter 7: Multi-Step Equations
- Explorations in Core Math Grade 8 - Chapter 8: Graphing Lines