Understanding the Area of a Pentagon

The video tutorial explains how to find the area of a pentagon by decomposing it into a rectangle and a triangle. It provides step-by-step calculations for the areas of these shapes using their respective formulas. The final area of the pentagon is calculated by summing the areas of the rectangle and triangle, resulting in a total area of 112 square units.

What is the first step in finding the area of a pentagon with no direct formula?

• Decompose it into simpler shapes

• Calculate the perimeter

• Measure each side

• Use the formula for a circle

Tags

CCSS.1.G.A.2

Into which two shapes is the pentagon decomposed?

• Two triangles

• A circle and a rectangle

• A rectangle and a triangle

• A square and a triangle

Tags

CCSS.3.MD.C.7B

CCSS.4.MD.A.3

What is the formula for the area of a rectangle?

• Base times height

• Side squared

• Length times width

• One half base times height

Tags

CCSS.6.G.A.1

What is the formula for the area of a triangle?

• Side squared

• One half base times height

• Base times height

• Length times width

Tags

CCSS.4.MD.A.3

What are the dimensions of the rectangle in the pentagon?

• 10 units by 5 units

• 14 units by 7 units

• 12 units by 6 units

• 8 units by 4 units

What is the base length of the triangle in the pentagon?

• 10 units

• 7 units

• 5 units

• 4 units

What is the height of the triangle in the pentagon?

• 6 units

• 5 units

• 4 units

• 3 units

Tags

CCSS.6.G.A.1

What is the area of the rectangle in the pentagon?

• 98 square units

• 112 square units

• 56 square units

• 84 square units

Tags

CCSS.6.G.A.1

What is the area of the triangle in the pentagon?

• 28 square units

• 14 square units

• 21 square units

• 35 square units

Tags

CCSS.6.G.A.1

What is the total area of the pentagon?

• 98 square units

• 126 square units

• 112 square units

• 84 square units

Tags

CCSS.6.G.A.1