Challenge 5.1: Construct an isosceles triangle

One star: Moving points around the grid
Three star: Using fixed circles, radii, and segments

Challenge 4: Side-Angle-Side Triangles - Show that two triangles that have two sides equal and the angles between the sides also equal, have the equal third sides and also the two remaining angles are equal.

Three stars: Any way you can do it!

Use the "measurement" tool to verify your answer.

Unlocks "duplicate triangles" tool for any triangles that have the same side-angle-side!

The Concept

Turn Geometry into a game by introducing challenges, with stars for increasing difficulty and a certain number of stars "unlocking" capabilities to make future challenges easier.

Primary application is Geometry Pad, a sketchpad for iPad and Android tablets.

Challenge 3: Chopping line segments - Given two line segments, on the longer one place a point that divides the longer segment into two lengths, one of which is the same length as the shorter one.

One star: Moving points around the grid
Two star: Moving circles and radii around the grid
Three star: Using fixed circles, radii, and intersections

Challenge 2: Copy a line segment - Given a line segment and a randomly placed point, create a line segment extending from the point that is the same length as the original

One star: Moving points around the grid
Two star: Moving circles and radii around the grid
Three star: Using fixed circles, radii, and intersections

Three stars unlocks the "duplicate line segment" tool!

Challenge 1: Create an equilateral triangle

One star: Moving points around the grid and creating line segments between them
Two star: Moving circles and radii around the grid
Three star: Using fixed circles, radii, and intersections, with no sliding of objects

Three stars unlocks the "equilateral triangle" tool!