Free 3-dimensional points Calculator - Calculates distance between two 3-dimensional points
(x₁, y₁, z₁) and (x₂, y₂, z₂) as well as the parametric equations and symmetric equations

Free Angle Ratio for a Triangle Calculator - Given an angle ratio for a triangle of a:b:c, this determines the angle measurements of the triangle.

Free Annulus Calculator - Calculates the area of an annulus and the equation of the annulus using the radius of the large and small concentric circles.

Free Bretschneiders Formula Calculator - Calculates the area of a quadrilateral using Bretschneiders Formula

Free Cardioid Calculator - Shows you the area, arc length, polar equation of the horizontal cardioid, and the polar equation of the vertical cardioid

Free Cevian Triangle Relations Calculator - Given a triangle with a cevian, this will solve for the cevian or segments or sides based on inputs

Free Chord Calculator - Solves for any of the 3 items in the Chord of a Circle equation, Chord Length (c), Radius (r), and center to chord midpoint (t).

Free Circles Calculator - Calculates and solves for Radius, Diameter, Circumference, and Area of a Circle.

Free Clock Angle Calculator - Calculate the angle on a clock between the hour and minute hands or how many times on the clock form an angle of (x°) between the minute and hour hand (backwards and forwards). Clock Angle Calculator

Free Clock Hands Meet Calculator - Calculates the first time on a clock when the hands will meet or touch again.

Free Cones Calculator - Calculates and solves for Radius, height, Volume (Capacity), Lateral Area, and Surface Area of a Cone.

Free Consecutive Interior Angles Calculator - Shows you a proof of consecutive interior angles using parallel lines and a transversal

Free Cube Calculator - Solves for Volume (Capacity), Lateral Area,Surface Area, and the value of a side for a cube.

Free Cuboid Calculator - Calculates the volume, surface area, diagonals, and space diagonal for a cuboid

Free Cylinders Calculator - Calculates and solves for Radius, Diameter, Volume (Capacity), Lateral Area, and Surface Area of a Cylinder.

Free Decagon Calculator - Solves for the side, perimeter, and area of a decagon.

Free Equilateral Triangle Calculator - Given a side (a), this calculates the following items of the equilateral triangle:
* Perimeter (P)
* Semi-Perimeter (s)
* Area (A)
* altitudes (h_a,h_b,h_c)
* medians (m_a,m_b,m_c)
* angle bisectors (t_a,t_b,t_c)
* Circumscribed Circle Radius (R)
* Inscribed Circle Radius (r)

Free Euclidean Geometry Calculator - Shows you the area, arc length, polar equation of the horizontal cardioid, and the polar equation of the vertical cardioid

Free Eulers Formula for Planar Geometry Calculator - This calculator solves for any one of the 3 following items using Eulers Formula for planar geometry:
* Vertices (v)
* Faces (f)
* Edges (e)

Free Geometric Mean of a Triangle Calculator - Given certain segments of a special right triangle, this will calculate other segments using the geometric mean

Free Golden Ratio Calculator - Solves for 2 out of the 3 variables for a segment broken in 2 pieces that satisfies the Golden Ratio (Golden Mean).
(a) Large Segment
(b) Small Segment
(a + b) Total Segment

Free Hemisphere Calculator - Calculates the base circumference, volume, curved surface area, base surface area, total surface area of a hemisphere with radius r

Free Heptagon Calculator - Solves for side length, perimeter, and area of a heptagon.

Free Hexagon Calculator - This calculator solves for side length (s), Area (A), and Perimeter (P) of a hexagon given one of the 3 entries.

Free Isosceles Triangle Calculator - Given a long side (a) and a short side (b), this determines the following items of the isosceles triangle:
* Area (A)
* Semi-Perimeter (s)
* Altitude a (ha)
* Altitude b (hb)
* Altitude c (hc)

Free Kites Calculator - This calculates perimeter and/or area of a kite given certain inputs such as short and long side, short and long diagonal, or angle between short and long side

Free Nonagon Calculator - Calculates the side, perimeter, and area of a nonagon

Free Octagon Calculator - Calculate side, area, and perimeter of an octagon based on inputs

Free Pentagons Calculator - Given a side length and an apothem, this calculates the perimeter and area of the pentagon.

Free Pick's Theorem Calculator - This calculator determines the area of a simple polygon using interior points and boundary points using Pick's Theorem

Free Plane Geometry Operations Calculator - Evaluates and simplifies various plane geometry notation and operations

Free Polygon Side Calculator - Determines the sides of a polygon given an interior angle sum.

Free Polygons Calculator - Using various input scenarios of a polygon such as side length, number of sides, apothem, and radius, this calculator determines Perimeter or a polygon and Area of the polygon. This also determines interior angles of a polygon and diagonals of a polygon as well as the total number of 1 vertex diagonals.

Free Pyramids Calculator - Solves for Volume (Capacity), Surface Area, height, or radius of a Pyramid.

Free Quadrilateral Calculator - Given 4 points entered, this determines the area using Brahmaguptas Formula and perimeter of the quadrilateral formed by the points as well as checking to see if the quadrilateral (quadrangle) is a parallelogram.

Free Rectangles and Parallelograms Calculator - Solve for Area, Perimeter, length, and width of a rectangle or parallelogram and also calculates the diagonal length as well as the circumradius and inradius.

Free Rectangular Solid Calculator - Solves for Volume (Capacity) of rectangular solid
Lateral Area of rectangular Solid
Surface Area of rectangular solid.

Free Rhombus Calculator - Given inputs of a rhombus, this calculates the following:
Perimeter of a Rhombus
Area of a Rhombus
Side of a Rhombus

Free Right Triangles Calculator - This solves for all the pieces of a right triangle based on given inputs using items like the sin ratio, cosine ratio, tangent ratio, and the Pythagorean Theorem as well as the inradius.

Free Special Triangles: Isosceles and 30-60-90 Calculator - Given an Isosceles triangle (45-45-90) or 30-60-90 right triangle, the calculator will solve the 2 remaining sides of the triangle given one side entered.

Free Spheres Calculator - Calculates and solves for Volume (Capacity), Surface Area, and Radius of a Sphere.

Free Squares Calculator - Solve for Area of a square, Perimeter of a square, side of a square, diagonal of a square.

Free Tetrahedron Marble Problem Calculator - Word problem using marbles in a cylinder jar that forms a tetrahedron.

Free Torus Calculator - Calculates the volume of a torus and surface area of a torus given major radius and minor radius.

Free Trapezoids Calculator - This calculator determines the following items for a trapezoid based on given inputs:
* Area of trapezoid
* Perimeter of a Trapezoid

Free Triangle Coordinate Items Calculator - Enter 3 points for the vertices of a triangle, and this will calculate the area of that triangle and the centroid.

Free Triangle Inequality Calculator - This calculator displays 2 scenarios
1) Enter 3 sides of a triangle, and it will determine if the side lengths satisfy the properties of the triangle inequality and form a triangle
2) Enter 2 sides of a triangle, and this will determine an acceptable range for the length of the 3rd side of a triangle so that the 3rd side respects the Triangle Inequality.

Free Triangles Calculator - This lesson walks you through the basics of a triangle and shows you triangle types like acute, right, obtuse, scalene, isosceles, equilateral.

Free Two Column Proof Calculator - Shows you the details behind a two column proof including the five parts and examples

Free What is a Line Calculator - This lesson walks you through what a line is and the various implications of a line in geometry

Free What is a Perpendicular Bisector Calculator - This lesson walks you through what a perpendicular bisector is and the various properties of the segment it bisects and the angles formed by the bisection

Free What is a Point Calculator - This lesson walks you through what a point is and the various implications of a point in geometry

Free What is a Ray Calculator - This lesson walks you through what a Ray is and the various implications of a ray in geometry

Free What is a Segment Calculator - This lesson walks you through what a segment is and the various implications of a segment in geometry including the midpoint of a segment.

Free What is an Angle Calculator - This lesson walks you through what an angle is and how to use it