Calculating Triangle Areas Methods

In this lesson, students are tasked with finding the areas of triangles using various strategies. They are encouraged to work independently and discuss their findings with a partner. The video introduces three main strategies: enclosing the triangle in a rectangle, decomposing the triangle into smaller rectangles, and duplicating the triangle to form a parallelogram. Each method involves calculating areas and using geometric properties to find solutions. The lesson concludes with encouragement to try different strategies and explain the reasoning behind them.

What is the main task given in this lesson?

• Measure the angles of a pentagon.

• Find the perimeter of a square.

• Calculate the volume of a cube.

• Find the areas of at least two triangles.

Which strategy involves enclosing a triangle in a rectangle?

• Decomposing the triangle into smaller triangles.

• Using a circle to approximate the area.

• Enclosing the triangle in a rectangle.

• Duplicating the triangle to form a parallelogram.

How do you find the area of a triangle using the rectangle method?

• Subtract the area of the rectangle from the triangle.

• Add the area of the rectangle to the triangle.

• Take half the area of the rectangle.

• Double the area of the rectangle.

What is the first step in decomposing a triangle into smaller rectangles?

• Calculate the perimeter of the triangle.

• Draw a circle around the triangle.

• Duplicate the triangle.

• Draw small rectangles within the triangle.

When decomposing a triangle into rectangles, what do you do after finding the area of each rectangle?

• Multiply the areas together.

• Subtract the smaller area from the larger one.

• Take half of each area and add them together.

• Divide the total area by two.

What shape is formed when you duplicate a triangle to find its area?

• A square.

• A parallelogram.

• A circle.

• A hexagon.

How do you calculate the area of a triangle using the parallelogram method?

• Subtract the area of the parallelogram from the triangle.

• Double the area of the parallelogram.

• Take half the area of the parallelogram.

• Add the area of the parallelogram to the triangle.