Study Guide

# Basic Geometry Topics

### Basic Shapes

This is where it all begins: basic shapes, lines, and angles.

### Angles

Not to be confused with angels, angles are the pointed corners of shapes. Angles can be named...

### Parallel Lines & Transversals

A transversal is a line, or line segment, that intersects two or more other lines, or line...

### Polygons

A polygon is any closed figure with three or more straight sides. "Closed" means that there are...

### Triangles

Triangles are three-sided polygons, but we're sure that you already knew that. The triangle is...

### Quadrilaterals

Quadrilaterals are four sided shapes. The most common include squares and rectangles, but there...

### Angles in a Polygon

As we discussed before, the three angles of a triangle always add up to 180°.In each...

### Circles

A circle is the set of all points equal in distance from a center point. If you pinned a piece of...

### Similar Figures

Similar figures are always the same shape, but not the same size. They have equal angles but not...

### Congruent Figures

Congruent figures have the same shape and size, they're totally equal. Same-same. All of the...

### Perimeter & Circumference

The perimeter of a shape is the distance around the outside of the figure. It's pretty simple;...

### Area (Polygon, Triangle, Circle, Square)

Area is the amount of space inside a two-dimensional shape. If you think about the floor of your...

### Area Formulas

Let's go over these area formulas one more time.Area of a Rectangle = Base × HeightArea of...

### Area of Irregular Shapes

In real life figures are often irregular shapes - a little bit messy. Think of your messy bedroom...

### 3D Objects (Prisms, Cylinders, Cones, Spheres)

Three‐dimensional objects are the solid shapes you see every day, like boxes, balls, coffee...

### Volume of Prisms & Cylinders

The volume of a solid is the amount of space inside the object. It's how much water fits inside a...

### Volume of Pyramids & Cones

The formula for the volume of pyramids and cones tells you how much space is inside each...

### Volume of Spheres

A ball is a sphere. A sphere is a 3-D shape. 3-D shapes have volume. So a ball has volume. What...

### Surface Area

Surface Area of a Cone = πr2 + πrsTo find the surface area of a cone, we need to find the...

### Pythagorean Theorem

A long time ago, in ancient Greece, a brilliant guy named Pythagoras discovered something...