Hi Chelsea, welcome to your Geometry Lab.
Everything from class is here. Drag the angles, bend the triangles, spin the solids, then test yourself. Wrong answers are fine. They show you what to look at again.
Straight lines, rays and segments
A straight line goes on forever in both directions. A ray starts at one point and goes on forever one way. A line segment has two end points, so you can measure it. Pick one and tilt it.
Move the arm, name the angle
An angle is the amount of turn between two arms that meet at a point. We measure it in degrees. Grab the pink arm and turn it. The lab tells you the size and the name.
Flat shapes and solid shapes
2D shapes are flat. They have length and width only. 3D shapes are solid. They also have height, so you can hold them. Tap a flat shape to count its sides and corners.
Are all the sides and angles equal?
A regular shape has all sides equal and all angles equal. If even one side or one angle is different, the shape is irregular. Change the number of sides, then switch between regular and irregular.
Types of triangles
Triangles get their names from their sides: equilateral (3 equal sides), isosceles (2 equal sides) and scalene (no equal sides). They also get names from their angles: acute, right or obtuse. The three angles always add up to 180°.
Equilateral
3 equal sides. 3 equal angles of 60°.
Isosceles
2 equal sides. The 2 angles opposite them are equal too.
Scalene
No equal sides. No equal angles.
Matching tick marks mean equal sides. Different tick marks mean different lengths.
Angles on parallel lines
Parallel lines never meet. They stay the same distance apart, like railway tracks. A line that cuts across them is a transversal. It makes eight angles, and some of them are always related. Move the slider and watch the pairs.