Perimeter and Area

By F. West

ObjectivesStudents will understand the meaning of perimeter & area and apply it in problems. GLEC Standards and Benchmarks

M.UN. 03.05 II .3.2

3 grade math

Learning Resources and Materials

Ruler

Graph paper

Methods and ProcedureThe teacher will introduce vocabulary, and demonstrate how to solve perimeter and area problems.

IntroductionStep 1. Activate Prior Knowledge

What do you know about perimeter and area?

What is perimeter?The distance measured around an object.

Look at the objects belowYou can use a ruler to measure shapes.

Perimeter

Use the graph paper to draw some triangles and measure them.

PerimeterThe formula to solve a triangle is P = a+b+c

Perimeter

A B

C

Find the Perimeter

10cm 10cm 8cm 8cm

10cm 8cm

What is the area?The number of square units needed to cover a shape

What is the formula to solve the area of a triangle?A=½ hxb or A= hxb

2

6cm

4cm

Area

Find the Area

5cm 3cm

4cm 4cm

Area = Area =

Find the perimeterP= 2L+2W

5

5 5

5

Find the Perimeter

5cm 11cm

5cm 11cm

Find the AreaA=LxW

12 cm

4cm

AssessmentCompute the area, go to

http://www.mathgoodies.com/lessons/vol1/area-triangle-part3.html

Compute the perimeter and area of shapes, go to

http://www.mathgoodies.com/lessons/vol1/perim_part3.html

Resourceshttp://www.helpingwithmath.com/printables/worksheets/geo0601area02.htm

http://www.mathgoodies.com/lessons/vol1/area-triangle-part2.html

http://www.michigan.gov/documents/mde/3rd_Math_357689_7.pdf

http://office.microsoft.com/en-us/images/?CTT=97