What is perimeter? Which units we use to show it?
Perimeter is the distance around a polygon.
It's the sum of all the sides of a polygon.
We use linear units such as: mm, cm, m, km,
What is the formula to find the area of a rectangle?
Area = base x length
What is the formula for area of a parallelogram?
A = base x height
What is the formula to find the area of a triangle?
Area = base x height / 2
What do you need to do to find the Surface Area of a triangular prism?
To find the surface area of a triangular prism you need to find the area of its 5 faces and add them.
Find the perimeter of this square.
Perimeter = 12 cm
Find the area of this square:
Area = 9 cm2
Find the area of this parallelogram.
A = b x h = 8 x 4
A = 32 cm2
Find the area of this triangle.
A = b x h /2
A = 10 x 7 /2
A = 35 cm2
What is the formula to find the volume of a triangular prims?
Volume = Base area x length =
Volume = width x height /2 x length
Find the perimeter of this parallelogram:
Perimeter = (6 + 11) x 2 = 34 cm
Find the perimeter of this rectangle.
Perimeter = (2,20 + 1.85) x 2 = 8.1 cm
Which figure is not a parallelogram? Why?
Figure 2 because it does not have 2 pairs of parallel sides.
Find the area of this triangle.
A = b x h /2
A = 14 x 5 /2
A = 35 square units
What is the volume of a triangular prism with base area 50 m2 and length 20 m?
Volume = base area x length
Volume = 50 m2 x 20 m2
V = 1000 m3
Teacher Elys ran around Ibirapuera Park. She ran only 7 km. The distance she ran was 50% of the perimeter of the park. What is the perimeter of the park?
50% = 7km
100% = 14 km
The perimeter of the park is 14km.
The area of this rectangle is 42 cm2. Find the missing side.
42 = 6 x width
width = 7 cm
The area of this parallelogram is 42 cm2. Find the missing height.
A = b x h
42 = 6 x h
h = 7 cm
Find the area of this triangle.
A = b x h /2
A = 7 x 6 /2
A = 21 cm2
Find the volume of this triangular prism.
Volume = base area x length
V = 12 x 16 /2 x 10
V = 96 x 10 = 960
Volume = 960 cm3
It costs $20/m to fence a tennis field. How much it would cost to fence a tennis field with perimeter of 480m?
It would cost $20 x 480 = $9600
The perimeter of this rectangle is 56 cm. Find the missing side s?
Perimeter = 20 + 20 + 2s
56 cm2 = 40cm + 2s
s = 16 /2
s = 8 cm
The parallelogram shown below has area 135 m2. Find the missing base.
A = base x height
135 = b x 15
b = 9 m
The area of this triangle is 80 m2. Find the missing height.
A = b x h /2
80 = 20 x h /2
160 = 20 x h
h = 160 /20
h = 8 m
Find the surface area of this triangular prims.
Area of the 2 triangles: 2 x ( 8 x 6 /2 ) = 48 cm2
Area of rectangle 1: 4 x 8 = 32 cm2
Area of rectangle 2: 4 x 10 = 40 cm2
Area of rectangle 3: 4 x 6 = 24 cm2
Surface Area = 48 + 32 + 40 + 24 = 144 cm2