Objective Students will solve practical area and perimeter problems involving composite plane figures.

Essential Questions How does knowing the perimeter and/or circumference and areas of polygons and circles assist in calculating the perimeters and areas of composite figures? The perimeter of a composite figure can be found by subdividing the figure into triangles, rectangles, squares, trapezoids and/or semicircles, and calculating the perimeter using the appropriate measurements. The area of a composite figure can be found subdividing the figure into triangles, rectangles, squares, trapezoids and/or semicircles, and calculating their area and adding areas together.

- A simple, closed plane figure with sides that are line segments.

Some examples of polygons

Circumference Is the distance around the circle.

Composite figures Are made up of distinct components such as polygons and semi circles. Semi-circle

Area A flat space or surface

Formulas for AREA Area (A) of a rectangle is computed by multiplying the lengths of two adjacent sides A= 7 * 5 = 35 cm^2 7 cm 5 cm

Formulas for AREA Parallelogram is computed by multiplying the measure of its base by its height. 13 in 17 in A= b x h A= 17 x 13 A= 221^2 in

Formulas for AREA Area of a Triangle is computed by multiplying the measure of its base by the measure of its height and dividing the product by 2. 6cm 8cm A= 8 * 6 2 A= 24 A= ½ * 6 * 8 A= 3 * 8 A= 24cm^2

Formulas for AREA Trapezoid is computed by taking the average of the measures of the two bases and multiplying this average by the height. 5 in 2.5 in 6 in Perimeter = 20 cm A= ½ ( ) * 5 A= in

Formulas for AREA Area of CIRCLE is computed by multiplying π (pi) times the radius squared. ( A = π r^2) A= 3.14 x 10 ^2 A= 3.14 x 100 A = 314

Formulas for AREA The Area semi-circle is computed by taking half of the Area. A= 3.14 x 10 ^2 A= 3.14 x 100 A = 314 A= 157

Formulas for AREA Circumference of a circle is found by multiplying π by the diameter or multiplying π by two times the radius

Formulas for Area Parallelogram A=bh Triangle A=1/2 bh Trapezoid A=1/2h(b 1 +b 2 ) Circle A=∏r 2

Don’t be scared

It won’t hurt a bit

What is this? Areas is the space around an item. Composite Figures are figures made of two or more figures.

Yea I know how to find area of a shape Parallelogram A=bh Triangle A=1/2 bh Trapezoid A=1/2h(b 1 +b 2 ) Circle A=∏r 2

32.5cm

Ok… So? You said a composite figure was two or more shapes?

Right so look at the figure what two shapes create it? What two shapes make up this figure?

What did you see? Square and Triangle

What the next step? Area of the square=bh A=10x10 Area of Triangle=1/2bh A=1/2x6x10  Where did you find that 10?

The area is 100 and 30, right? But what about the whole figure? We need to add the two sums =130cm 2

Try this one. What shapes do you see?

What is the area of them? Circle=∏r 2 Triangle =1/2bh

Does that circle look like a whole? What are you going to do the answer you find?

Did you get a sum of 13.3in 2 ? Area of semicircle A =  r 2 A =  · 2 2 A  12.6 Take 1/2 A  6.3 Area of triangle A = bh A = 4x 3 x 1/2 A = 7

Well Think you Got IT?