Math Is Fun
Math Is Fun: Heron's Formula
Learn a formula, created thousands of years ago, that you can use to calculate the area of a triangle if you know all three sides' lengths.
Science Buddies
Science Buddies: M&m Geometry
Geometry is the study of how to use math to describe and investigate different points, lines and shapes. The way that a shape is described in geometry is with a formula, which is simply a mathematical way to calculate different...
Analyze Math
Analyze Math: Area of Triangles
The geometry resource explores the different formulas used to calculate the area of triangles. The applet investigates the angles and sides of a triangle.
CK-12 Foundation
Ck 12: Geometry: Surface Area of Cylinders
[Free Registration/Login may be required to access all resource tools.] Use a formula and given information to find the surface area of different cylinders.
CK-12 Foundation
Ck 12: Geometry: Surface Area of Triangular Prisms
[Free Registration/Login may be required to access all resource tools.] Use formulas to find the surface area of triangular prisms.
CK-12 Foundation
Ck 12: Geometry: Surface Area and Volume of Cones
[Free Registration/Login may be required to access all resource tools.] Use a formula and given information to find the surface area of cones and truncated cones.
CK-12 Foundation
Ck 12: Geometry: Surface Area and Volume of Pyramids
[Free Registration/Login may be required to access all resource tools.] Find the surface area of pyramids by using formulas
CK-12 Foundation
Ck 12: Geometry: Surface Area and Volume of Pyramids
[Free Registration/Login may be required to access all resource tools.] Use a formula and given information to find the surface area of pyramids.
Sophia Learning
Sophia: Finding a Formula for the Volume of a Cylinder
Use prior knowledge of a rectangular prism to determine the formula of a cylinder. Check for understanding with the assessment at then end of lesson.
Khan Academy
Khan Academy: Area of Parts of Circles
Practice problems finding area of parts of circles.
Khan Academy
Khan Academy: Problem Solving With Area and Circumference of Circles
In this exercise, students practice problem solving the area and circumference of circles. Students receive immediate feedback and have the opportunity to get hints and try questions repeatedly.
Shmoop University
Shmoop: Basic Geometry: Surface Area
The geometry resource investigates surface area. Formulas, examples, and practice exercises are included.
Mr. Martini's Classroom
Mr. Martini's Classroom: Area of Triangles, Trapezoids & Parallelograms
Students solve for the area of rectangles, squares, triangles, trapezoids, and parallelograms.
National Council of Teachers of Mathematics
The Math Forum: Elementary Geometry Circles
The Math Forum offers an archive of question and answer sessions on circles and how they relate to geometry.
Math2
Math2.org: Areas, Volumes, Surface Areas
This site gives formulas for the area, volume, and surface area of various shapes.
Texas Instruments
Texas Instruments: Using the Distance Formula to Find Trapezoidal Area
This activity can be used as a formative assessment review of algebra and coordinate geometry.
Purple Math
Purplemath: Geometric Formula Review
Need to freshen up on your geometric formulas? This explanation focuses on some basic formulas that should be committed to memory such as area, volume, perimeter, and more.
Other
Calculating the Surface Area of a Cone
This site explains a method for finding the surface area of a cone. It has several plane geometry formulas.
Math Open Reference
Math Open Reference: Parallelogram: (Coordinate Geometry)
Students are able to manipulate a parallelogram on a coordinate grid to explore properties of a parallelogram and then calculate the distance of the sides, altitude, and area. The resource also includes links to further explain important...
Texas Instruments
Texas Instruments: The Area of the Trapeziod
This activity is a based on an activity I saw in Exploring Geometry with the Geometer's Sketchpad. Student will construct a trapeziod and then use rotation to create a parallelogram from the trapeziod. The follow up questions lead the...
CK-12 Foundation
Ck 12: Geometry: Surface Area of Rectangular Prisms
[Free Registration/Login may be required to access all resource tools.] Find the surface area of rectangular prisms by using formulas
CK-12 Foundation
Ck 12: Geometry: Circumference and Arc Length Study Guide
This study guide on circumference and arc length covers key vocabulary, the parts of a circle, and formulas for circumference, area, and arc length. It is available for download with free registration.
University of Illinois
University of Illinois Urbana Champaign: The Geometry Center: Area of Quadrilaterals
Formulas on calculating the area of a general quadrilateral and special cases of quadrilaterals.