Geometry

Prisms A prism is a polyhedron with two parallel, identical faces (called bases), and whose remaining faces (called lateral faces) are parallelograms. The lateral faces are formed by joining corresponding vertices of the bases. The altitude (height) of a prism is the perpendicular distance between the bases. To find the…

Let’s review the anatomy of a circle: Radius (r) is the distance from the center of the circle to the closed curve. Diameter (d) is the distance measured across the circle through the center. The diameter is often represented at d = 2⋅r since it’s twice the radius. Central angle is one whose…

A quadrilateral is a polygon (i.e. 2D shape) with four edges (or sides) and four vertices or corners. Examples of quadrilaterals are illustrated below. In this section, we’ll focus on finding the area of trapezoids (right). A comparison of how to find the area of different quadrilaterals, namely the parallelograms (left) and rhombuses (center) are also…

Triangles are polygons with three sides. The angles between the sides are the interior angles. The total sum of interior angles of any triangle equals 180°. Let’s take a look at some common triangles and their characteristics. A scalene triangle is one in which all three angles are different, therefore all…

A polygon is a plane figure formed by three or more line segments. The points where the sides meet are called vertices, and sum of the lengths of a polygon’s sides is its perimeter. If all of the sides and angles of a polygon are equal, it is called a regular…

Much of this section can be summarized using the diagram: Notice how lines 1 and 2 (denoted L1 and L2) are parallel (they never intersect), and that’s indicated by red arrows. Line T is called the transversal, it simply cuts through L1 and L2. How each of these angles are related…