Corbett Maths
Loci Part 1
Where can it go? The first video on loci develops a definition and provides some quick sketches of the loci of all points with given characteristics. The presenter does an example of the loci of points a given distance from an L shape.
Corbett Maths
Loci Part 2
Closer to this point and farther from that one. Continuing with loci problems, a short video shows how to work problems that are not straightforward. The presenter works loci problems that result in a region that meets several criteria.
Corbett Maths
Construct a 45 Degree Angle
Create a 45-degree angle without bisecting an angle. A video shows a method to construct a 45-degree angle without needing to bisect a right angle. By constructing an isosceles right triangle, the presenter constructs a 45-degree angle...
Corbett Maths
Perpendicular Through a Point on a Line
Use one construction to complete a second. The short video shows how to incorporate the steps of a perpendicular bisector to create a perpendicular to a point on a line. With their own straightedges and compasses, classmates then...
Corbett Maths
Perpendicular Bisector
Where should the statue be located? The resource explains how to use a compass and straight-edge to construct the perpendicular bisector of a line segment. Using an exam question, the narrator models how to solve an application problem...
CK-12 Foundation
Perpendicular Bisectors: Lesson
Get right up and split it in half. Using a diagram, the video provides the definition of a perpendicular bisector. The portion in a playlist on basic geometry explains perpendicular bisector of a segment and of triangle sides properties.
CK-12 Foundation
Isosceles Triangles: Lesson
Two sides give us two angles. A segment of a playlist on basic geometry revisits isosceles triangles. The presentation explains several properties and theorems related to isosceles triangles.
Curated OER
How Do You Write an Equation of a Line in Slope-Intercept Form If You Have One Point and a Perpendicular Line?
This problem has many steps involved. Finding equations and rearranging equations. Finding slope and getting the opposite reciprocal of a slope. Finding intercepts. There's a lot to do to solve this problem. It's not so difficult, it...
Corbett Maths
Circle Theorems
Circles are ripe with theorems. Viewers of a YouTube video watch as the narrator describes a set of eight theorems on circles. The video shows a diagram for each theorem and provides a brief explanation for each one.
Khan Academy
Khan Academy: Review of Triangle Properties
Provides a review of perpendicular bisectors, angle bisectors, medians, and altitudes and the special points of concurrency formed by these parts of a triangle. The points of concurrency are the circumcenter, incenter, centroid,and...
Khan Academy
Khan Academy: Perpendicular Bisectors: 2003 Aime Ii Problem 7
Finding the area of a rhombus based on the circumradii of triangles.
Khan Academy
Khan Academy: Perpendicular Bisectors: Area Circumradius Formula Proof
Proof of the formula relating the area of a triangle to its circumradius.