Maths Challenge
Maths challenge.net: Christmas Trees
Find how many Christmas trees can be planted using your conversion and geometric knowledge.
Maths Challenge
Maths challenge.net: Cables
This is a proof problem, considered a "three star" geometry problem requiring knowledge of proofs and properties of circles to solve this problem with cables in duct problem.
Maths Challenge
Maths challenge.net: Radical Axis
This is a "three star" geometry problem requiring knowledge of proofs and properties of circles. Students will use the given definition of radical axis and prior knowledges to prove a way to find a radical axis.
Maths Challenge
Maths challenge.net: Unique Circle Equal Angles
A "three star geometry problem" - requiring the knowledge of biconditional statements and how to prove such problems.
Wolfram Research
Wolfram Math World: Rectangle
MathWorld provides the definition of a rectangle and the area formula of a rectangle.
Maths Challenge
Maths challenge.net: Tiled Floor
An area problem involving diagonals of a tiled floor.
Maths Challenge
Maths challenge.net: Shaded Square
A problem of finding the fraction of a square that is shaded given criterion. Students will have to use their mathematical reasoning and triangle solving skills to solve this area problem.
Maths Challenge
Maths challenge.net: Shaded Hexagon
A problem with equilateral triangles and area to solve this "Shaded Hexagon" problem. Mathematical reasoning and triangle knowledge will be needed to solve the problem.
Maths Challenge
Maths challenge.net: Corner Circle
This is a "three star" geometry problem where prior knowledge of circles and triangles is recommended to solve this circle in the corner problem.
Maths Challenge
Maths challenge.net: Shaded Cross
Find the area of this tilted cross with your geometry skills.
Maths Challenge
Maths challenge.net: Curvature of the Earth
Distance problem using a spherical radius and height.
National Council of Teachers of Mathematics
The Math Forum: Geometry Turned On
This Math Forum site contains many mathematical and geometric explanations and proofs of many different topics that have been done using a geometry software called Geometer's Sketchpad. The explanations are very detailed and clear;...
Illustrative Mathematics
Illustrative Mathematics: G C Placing a Fire Hydrant
You have been asked to place a fire hydrant so that it is an equal distance from three locations on a map. Students must fold a paper so that this point is where two folds intersect, and they must explain why their construction works and...