Determine the perimeter of a complex shape

Perimeter- the distance around a shape

Obj. #45

Some common formulas for perimeter:

Square- P=4s or

P=s+s+s+s

Rectangle- P=2(l + w)

3cm

3cm

4x3=12cm ~or~

3+3+3+3= 12cm

2cm

6cm

2(2 +6)=16cm ~or~

2+6+2+6=16cm2cm

2.5cm

2.5c

m

2.5+2.5+2=7cm

Objective #45 (continued)

*The center shape is a square.

**The triangles are congruent.

3cm

3.5c

m I need to be sure to add

all sides

3+3.5+3.5+3.5+3.5+3=20cm

Determine the area of a complex shape

Area- The amount of space an object takes up

Obj. #46

Some common formulas for area:

Square- A=s2

A=s x s

Rectangle- A=l x w

Triangle- A=(bxh)/2

3cm

3cm

32=9cm2 ~or~

3x3=9cm2

2cm

6cm

3cm

6x2=12cm2

4cm

3x4=12/2=6cm2

Objective #46 (continued)

*The center shape is a square.

**The triangles are congruent.

3cm

I need to be sure to add the areas of all shapes

2cm

Square- 32=9cm2

Triangle 1- (3x2)=6 6/2=3cm2

Triangle 2- (3x2)=6 6/2=3cm2

Area of complex shape- 9+3+3=15cm2

WP: Determine the area or perimeter of a complex shape

Some ways to know if you need to find area or perimeter:

Anything that is fenced in or enclosed is perimeter

If you’re carpeting, cementing, painting, etc. you need to find area

Obj. #47