National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: "Impossible" Geometric Constructions
Three geometric constructions students like to say are "impossible" are explained here. Trisecting an angle, squaring a circle, and doubling a cube are examined as being either possible or impossible, depending on the "rules" you use.
PBS
Pbs: Slope and House Construction
Discover how math is required for quality construction when a Master Carpenter shares his experience and expertise. This video focuses on explaining slope as rise over run and shows how slope comes into play when building homes to take...
Illustrative Mathematics
Illustrative Mathematics: G Co Inscribing an Equilateral Triangle in a Circle
Suppose we are given a circle of radius r. The goal of this task is to construct an equilateral triangle whose three vertices lie on the circle. Aligns with G-CO.D.13.
Illustrative Mathematics
Illustrative Mathematics: g.c Inscribing a Circle in a Triangle Ii
This task focuses on a fact which comes out of the construction of the inscribed circle in a triangle: the angle bisectors of the three angles of triangle ABC all meet in a point. Aligns with G-C.A.3.
Illustrative Mathematics
Illustrative Mathematics: G Co Inscribing a Square in a Circle
In this lesson plan, students learn how to inscribe a square in a circle. Aligns with G-CO.D.13
Khan Academy
Khan Academy: Algebra I: Point Slope Form
Write equations in point-slope form given two pairs of values, and convert the equation into slope-intercept form. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Khan Academy
Khan Academy: Recursive Formulas for Arithmetic Sequences
Find the recursive formula of an arithmetic sequence given the first few terms. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.