Use a triangle area formula that works when the height is unknown. The eighth installment in a 16-part series on trigonometry revisits the trigonometric triangle area formula that previously was shown to work with the acute triangles....

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...

Unfortunately for young mathematicians, the world isn't made entirely of parallelograms, triangles, and trapezoids. After first learning the area formulas for these common shapes, students apply this new knowledge to...

Extend young mathematicians' understanding of area with a geometry lesson on trapezoids. Building on their prior knowledge of rectangles and triangles, students learn how to calculate the area of trapezoids and other...

Learners discover how to find missing sides and angles using trigonometry. Scholars first watch a video covering the Law of Sines and Cosines, as well as the area formula for a triangle. To test their knowledge, they complete a worksheet...

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,...

Scholars can use area formulas, but can they apply what they know about area? The lesson plan challenges learners to think logically while practicing finding area of shapes such as rectangles, circles, parallelograms, triangles, and...

Find the area of triangles, rectangles, and parallelograms using this metric worksheet.

Young mathematicians build an understanding of area and perimeter with their own two hands in a series of interactive geometry lessons. Through the use of different math manipulatives, children investigate the properties of...

Develop young mathematicians' knowledge of two- and three-dimensional shapes with this geometry workbook. From learning about the classifications of different shapes and figures to calculating their area, perimeter, and volume, this...

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.

This is a good model for learners to visualize triangles of the same base and height. They can can begin to comprehend that these triangles will have the same area no matter how the triangle is drawn. It is part of a series of resources...

Scholars learn how to determine the area of compound shapes by finding the areas of the basic shapes that make it up. Pupils find the areas by adding areas together or subtracting them.

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.

The 21st segment in a 28-part series provides learners with area problems involving composite figures. To find the solution, pupils must decide whether to add or subtract areas. The composite figures are composed of quadrilaterals,...

An exercise in finding the area of polygons by decomposing into triangles and composing into rectangles is the focus of this resource. Make several copies of the worksheet for each participant. Ask learners to use colored pencils to...

Give your scholars the support they need to work with formulas. A reference page offers definitions and picture examples of perimeter, area, surface area, volume, the Pythagorean theorem, a variety of shapes, and more. 

Expand area problems to incorporate prior knowledge. Pupils begin by reviewing the formulas for finding the area of parallelograms and triangles. The scholars apply previous learning of trigonometric ratios and the Pythagorean Theorem to...

It's time to show what you know! Individuals first review finding the area of polygons using the formulas from parallelograms to regular polygons. They then brush up on finding the area and circumference of circles, as well as reviewing...

Lateral area and surface area are simple concepts, but calculating them is not as easy! Using formulas, learners calculate lateral area and surface area for the same three-dimensional figures. The resource discusses the formula variables...

Scholars determine distances on the coordinate plane to find areas. The instructional activity begins with a proof of the formula for the area of a parallelogram using the coordinate plane. Pupils use the coordinate plane to determine...

Help learners understand that perimeter and circumference are one in the same. Learners apply their skills to determine the perimeter/circumference of triangles, rectangles, and circles. They then use the same strategy to find the...

It's a piece of pizza! Pupils learn about a sector of a circle as a slice of the circle and determine how to find its area. Scholars continue to find out how to calculate the segment of a circle based on the sector's area. At the end,...

All the 2-D and 3-D measurement work you need is in one location. Divided into three sections, the geometry lesson plans consist of visualization of three dimensions, classifying geometric figures, and finding surface area and volume....