Even though there is a wide variety of different triangles in the world, knowing a single equation allows us to find the area of each and every one of them. Follow along with this step-by-step presentation as Zoe clearly models how to...

Painting an irregular figure can be tricky if we don't know the exact area. This interactive presentation reveals that irregular figures can be broken into smaller, simple figures that use the area formulas. Go through two examples,...

It's always nice to have a plan B. Pupils investigate an alternate formula for the area of a triangle that uses sine. A set of challenge questions shows how the new formula relates to the well-known formula of (1/2)bh.

Solving triangles is a breeze. Young boat enthusiasts solve problems involving triangles in the context of sails on a boat. They must apply different strategies, including the Law of Cosines and area formulas.

In this geometry activity, 10th graders find the base, height, or area of a triangle. The one page interactive activity contains ten questions. Answers and hints are included. 

In this geometry worksheet, 10th graders determine the area of triangles and parallelograms. The one page interactive worksheet contains ten questions. Answers and hints are included. 

In this online math worksheet, high schoolers find the height of 5 triangles given their area. This excellent resource allows the students to check their answers, and to get "hints" should they run into difficulties. A terrific teaching...

Tenth graders are provided instructions, including a video, on calculating the surface area of a prism. The one-page interactive activity contains two worked questions. Answers are included. 

In this using proper tools worksheet, students answer a set of 10 multiple choice questions. Students may click on a link to see answers and may print worksheet out.

In this tools for problem solving worksheet, students complete a set of 10 multiple choice questions. Worksheet is labeled as a "post test." Answer link provided.

Demonstrates the logic behind the formula for the area of a triangle. Includes several practice problems and their explanations.

Define's Heron's Formula and provides examples for how to use the formula to calculate the area of a triangle.