AREA OF SOLIDS
Green group
 Homework for Thursday
 Workbook page 189
 Homework for Friday
 Booklet (you may do the work separately and then staple it
together…be sure to use the same font if you are doing it on
computer…and be sure to have all the answers on the last
page done correctly..double check them.
Answers to homework - 4306
Workbook
PYRAMIDS
Page 182
#18a) 60 b) 57.72 c) 2214
#19 105.72
#20) 397.4
#21)$2240
Textbook
Page 66
#2c)180
Workbook
CONES
Page 184
#27a) 31.42 b) 263.89
#28)138.23
#29) 45.24
#30)628.32
Textbook
Page 67
#4)2356.19
Workbook
SPHERES
Page 185
#37a)78.54 b)113.10
#38)132.73
#39)127.23
Textbook
Page 66
#2d)2827.43
Metric Units
UP the stairs you move decimal to the
LEFT
km
hm
dam
m
DOWN the stairs you move decimal
to the RIGHT
dm
cm
mm
DRUL = Down Right, Up Left
For each step you move the decimal 1 place left
or right depending on how you are moving
UNITS OF AREA
km2
hm2
dam2
m2
dm2
cm2
mm2
Each step requires moving 2 decimal places because ….
AREA is 2 dimensional
Follow the DRUL rules…down right up left.
Practise converting units
1345 mm =
_________m
0.895 hm =
________ mm
45.256 km =
________ dam
43.664 m =
________ cm
7895.209 dm = ________ hm
678.34 km2=
________ dam2
34.56 m2 =
________ cm2
445.998 km2 =
________ hm2
57980.3 mm2 =
________ m2
0.94857 dam2= ________dm2
Workbook page 177 #1,2
91- for Thursday
4306 – for Wednesday
306-05 for wednesday
Answers
1.345
89500
4525.6
4366.4
7.895209
6783400
345600
44599.8
0.0579803
9485.7
Area of a Prism
4 cm
2 cm
8 cm
Step 3 – Find TA (total area)
TA = Area of the bases + LA
TA = 2(16) cm 2+ 80 cm 2
TA = 32 + 80
TA = 112 cm 2
Step 1 – Find Area of Base
Abase = 8cm x 2 cm
Abase = 16 cm2
Step 2 – Find the LA
LA = Perimeter of base x height
LA = 20 cm x 4 cm
LA = 80 cm2
Can you find the area of the base when
it’s a regular polygon?
c
a
n
Yes…you CAN too !!!!!
Area = C A N
2
c = cote (side length)
a = apothem
n= number of sides
Example
Find the area of the base of a regular hexagonal prism.
c = 10 cm
a=8.7 cm
n = 6 sides
Area base = can
2
A base = 10 x 8.7 x 6
2
A base = 522
2
A base = 261 cm2
Find the total area of this prism
Pentagonal prism that has a height of 3cm
c = 20 cm
a = 4 cm
n = 5 sides
Step 1 – Find Area 1 Base
Abase = c a n
2
Abase = 20 x 4 x 5
2
Abase = 400
2
Abase = 200cm2
Step 2 – Find the LA
LA = Pb x h
LA = (20 x 5) x 3
LA = 100 x 3
LA = 300 cm2
Step 3 – Find the Total Area of the prism
TA prism = LA + 2(Abase)
TA prism = 300 cm2 + 2 (200 cm2)
TA prism = 300 cm2 + 400 cm2
TA prism = 700 cm2
Workbook page 178 # 3,4,5
Page 178 #3,4,5
#3
4.5 cm
Step 1 – Find Area of Base
Abase = L x W
Abase = 4.5 x 4.5
Abase = 20.25cm2
Step 2 – Find the LA
LA = Perimeter of base x height
LA = (4.5 x 4) x 4.5 cm
LA = 18 cm x 4.5cm
LA = 81cm2
Step 3 – Find the Total Area
TA = 2(Abase ) + LA
TA = 2(20.25) + 81
TA= 121.5 cm2
Answers to Workbook
Page 178
#4a) 72.72cm2 b) 108cm2 c) 190.8cm2
#5) 286.08cm2
Page 179
#6) 844.71cm2
# 7) 1107cm2
#8) 384cm2
Answers to Text book #2
Page 66
#2a) 15.12 cm2
Page 67
#3a) 238.77 cm2 b) 389.10cm2
#5a) 1649.36cm2
c) 2140cm2
Page 179 #7
9cm
a= 6.2cm
Area of base = can
2
Area of base = 9 x 6.2 x 5
2
Area of base = 279
2
Area of base = 139.5 cm2
LA= Pb x height
LA= (9 x 5) x 18.4
LA = 45 x 18.4
LA = 828 cm2
TA = 2(Area of base) + LA
TA = 2(139.5) + 828
TA = 279 + 828
TA = 1107 cm2
Area of a Cylinder
r =10 mm
Height = 50 mm
Workbook
Page 181 #14a,b,c
#15
Text #2
Page 66 #2a
Page 67 #3a,b,c
#5a
Page 68 #9b
Step 1 – Find Area of Bases
Base is a circle….
Area = π r2
Abase = π(102)
Abase = 314.16mm2
Step 2 – Find the Lateral Area
LA = Circumference of base x Height
LA = 2πr x Height
LA = 2π(10) x 50
LA = 62.83 x 50
LA = 3141.59 mm2
Step 3 – find the total area of the cylinder
TA = LA + 2 Abase
TA = 3141.59 + 2(314.16)
TA = 3141.59 + 628.32
TA = 3769.91 mm2
Homework corrections
Workbook
Page 181 #14a) 370.96cm2 b) 188.31cm2 c) 261.39cm2
#15 LA= 87.96 cm2 TA= 164.93cm2
Text #2
Page 66 #2a)15.12
67 #3a) 238.77
b)
Area of Pyramid
Apothem
15cm
Square base
12cm
Workbook
Page 182 #18 to 22
Textbook #2
Page 66 #1c
Page 67 #4
Step 1 –find area of base
A = L xW
A = 12 x 12
A = 144 cm2
Step 2 – Find LA
LA = Pb x apothem
2
LA = 48 x 15
2
LA = 360 cm2
Step 3 – Total Area
TA = LA + Area of Base
TA = 360 + 144
TA = 504 cm2
Area of a Cone
height
apothem = 12
radius= 4.5 cm
Workbook
Page 184 # 27-34
Step 1 – Find Area of Base
Area of base = πr2
Area of base = π (4.52)
Area of base = 63.62 cm2
Step 2 – Find the LA
LA = π r x apothem
LA = π (4.5) ( 12)
LA = 169.5 cm2
Step 3 – Find the TA
TA = LA + Area of base
TA = 169.5 + 63.62
TA = 233.27 cm2
How to find the dimensions of the
sector of a circle
a
s
r
r=a
s 360
Area of a Sphere
r = 7cm
TA = LA = 4πr2
r
TA = 4 π (72)
TA = 615.75cm2
What is the radius of a sphere that has an area of
452.39cm2
1st
Workbook = pyramids
Page 182 #18 to 21
Textbook #2
Page 66 #2c
2nd Workbook = cones
Page 184 # 27-30
Textbook #2
Page 67 #4
4306
3rd Workbook = spheres
Page 185 # 37-39
Textbook #2
Page 66 #2d
ALL this is for
THURSDAYS class,
you will be given 73 min to
work on this on Wednesday
TEST- Mon Mar 29
homework
1st Workbook = pyramids
Page 182 #18 to 22
Textbook #2
Page 66 #1c
2nd Workbook = cones
Page 184 # 27-34
Textbook #2
Page 67 #4
Green group
3rd Workbook = spheres
Page 185 # 37-42
Textbook #2
Page 66 #2d
This work will be for Fridays
class, you will be able to
work on it on
Thursday…ALL for
Friday..no exceptions
Homework for Monday 306-05
1st Workbook = pyramids
Page 182 #18 to 21
Textbook #2
Page 66 #2c
2nd Workbook = cones
Page 184 # 27-33
Textbook #2
Page 67 #4
3rd Workbook = spheres
Page 185 # 37-39,41
Textbook #2
Page 66 #2d
You have ALL class to
work on these
problems… finish ALL
for MONDAY
Test Tues Mar 30
Homework for Friday March 19
pyramids
Textbook #2
Page 66 #2c
Cones
Page 184 # 27-34
Textbook #2
Page 67 #4
Spheres
Page 185 # 37-42
Textbook #2
Page 66 #2d
yellow
For Next Thursday March 26 you
must also have the following
completed
Decomposable Solids
Workbook
Page 188
Page 189
Only find the area of the parts you can
touch from the outside
On Wed Mar 31 you will have an
assessment on Area much like the
questions on 188-189
Decomposable Solids Work
CorrectWorkbook
Page 189
7-11
Textbook #2
Page 68 #9b
Page 69 #15
Page 73 #1
Page 74 #6a,8b
Page 75 #11a
Page 81 #6a,7a
Page 82 #8, #12a
Math 306
Workbook page 210 #12
Text #2 page 81 #7a
page 82 #8b
#12a
FINISH FOR MONDAY
Show all work clearly
Be sure to label correctly the work that you
are doing