Maths challenge.net: Annulus

Need some challenging problem-solving work for your students in the following areas: Discrete, Geometry, Numbers, and Code Breaking? This is the place for an enormous database of problems aimed at high school age students. They are...

A challenging proof like geometry of finding the square inscribed in a triangle.

This is a "three star" geometry problem where prior math problem skills and proof experience is recommended to solve this "Perpendicular Construction" problem.

A "three star geometry problem" requiring knowledge of how to complete geometric proofs and some prior math skills to figure the shortest distance between the opposite corners of a cuboid.

A "three star" geometry problem which requires prior math problem solving skills and proof writing skills to solve this "Bag of Balls" radius of balls problem.

This is a "three star" geometry problem where prior math problem skills and proof experience is recommended to solve this relationship between the inverses of heights.

A "three star" geometry problem requiring some prior knowledge in math and proofs to maximize the area of an inscribed triangle in terms of the hypotenuse.

A "three star" geometry problem where some experience of math problem solving skills and knowledge of circles is recommended to solve this lunes (parts of a circles) area problem

A "three star geometry problem" requiring knowledge of how to complete geometric proofs and some prior math knowledge. This problem asks to prove that the mid points of any quadrilateral form a parallelogram.

This is a "three star" geometry problem where prior math problem skills and proof experience is recommended. Tile constructions may be used to solve this perimeter and area problem.