To find the area of a triangle, try to make a parallelogram using a copy of the triangle.

Make the following triangles on a geoboard. Remember that the pegs are equally spaced in a square grid. Compare the areas of the triangles. Aligns with 6.G.A.1.

Sixth graders find the area of rectangles, triangles, parallelograms, and trapezoids by using formulas or by composing into rectangles or triangles.

Explore and learn about the features and properties of a right triangle in this lesson. Includes examples and practice questions.

[Free Registration/Login may be required to access all resource tools.] This study guide looks at the definitions and units for perimeter, area, and circumference, and at the perimeter and area of different shapes, including regular...

Learn how to find the areas and perimeters of triangles and special quadrilaterals.

Use this calculator to find the sides, perimeter, area, semiperimeter, and altitude of an isosceles triangle.

Learn about the perimeter of a triangle with this helpful reference tool. Provides a detailed definition, an example, and an internet activity that enhances further explanation. Includes links to related topics.

This CoolMath resource provides an introduction to some Precalculus formulas.