Perimeter and Area of

Polygons

10.M.G.GPE.07

10.M.G.GPE.07

Use coordinates to compute perimeters of polygons and

areas of triangles and rectangles, e.g., using the distance

formula.

Anticipatory Set

On a sheet of paper, draw a right triangle. Put

lengths on each of the sides of your right

triangle. Find the area of your triangle.

Remember, Area =½ bh.

Big Ideas of the Lesson

Today, we are going to study perimeter of

polygons and area of triangles and rectangles

in a coordinate plane. We are going to learn

about distance formula to help us find perimeter

and area.

Introduction (Let’s Review)

Introduction (New Formula)

Introduction (More Review)

Introduction (More Review)

Introduction (More Review)

Example

Find the area of

triangle ABC.

Example Solution

Example Solution

Example

Find the area and

perimeter of

rectangle ABCD.

Example Solution

Example Solution

Example Solution

Example Solution

Notes

Thinking question:

How can you find the

perimeter of any

polygon? (Share out)

Notes

Answer to thinking

question:

Find all of the side

lengths using the

distance formula and

add them together! :)

Notes

Thinking question:

How can you find the

area of this figure?

(Share out)

Notes

Answer 1:

Use area of a

rectangle and

subtract out the area

of the unshaded

triangles.

Notes

Answer 2:

Find the area of the 5

rectangles and 4

triangles and add

them together.

Check-in

Draw the polygon

with the given

vertices. Find the

perimeter and

area of the

polygon.

Check-in Solutions

Check-in

Draw the polygon

with the given

vertices. Find the

perimeter and

area of the

polygon.

Check-in Solutions

Closure

Describe how to find the perimeter and area of

any polygon.