Chapter 8 Area

Question 1

Area of a rectangle

Answer 1

A=lw

Question 2

Area of a parallelogram

Answer 2

A=bh

Question 3

Area of a triangle

Answer 3

A=1/2bh

Question 4

Area of a trapezoid

Answer 4

A=1/2(b1+b2)h

A= m*h (median is (b1+b2)/2)

Question 5

Area of a Kite/Rhombus

Answer 5

A=1/2(d1*d2)

Question 6

Are of a Regular Polygon

Answer 6

A=1/2ap

Question 7

Area of a Circle

Answer 7

A=(Pi)r^2

Question 8

Area of a sector

Answer 8

As=x°/360°*(Pi)r^2

Question 9

Area of a square

Answer 9

A=s^2
Or
A=d^2/2

Question 10

Area of a segment

Answer 10

Asg=As-At

Asg=x°/360°*(Pi)r^2-1/2bh

Question 11

Area of an annulus

Answer 11

A=(Pi)R^2*(Pi)r^2

Area of the big circle minus the area of the little circle

Question 12

Lateral Area

Answer 12

LA=ph
Ex. Rectangular prism with a height of 15, and base edges with the length of 5 and 16.
LA=ph. LA=(5+5+16+16)15. LA=(42)15. LA=630u^2

Question 13

Total Area

Answer 13

Ex. Rectangular prism with a height of 15, and base edges with the length of 5 and 16. LA=630u^2
TA=LA+2B (B is the area of the base. In this case a rectangle)
TA=630+2(5*16). TA= 630+2(80). TA=630+160. TA=790u^2

Question 14

Lateral area of a pyramid

Answer 14

LA=1/2p(L) L is the slant height
Ex. A square pyramid with a slant height of 26 and base edges of 20.
LA=1/2(20+20+20+20)26. LA=1/2(80)26. LA=(40)26. LA=1040u^2

Question 15

Total area for a pyramid

Answer 15

TA=LA+B (only one base because a pyramid only has one base)
Ex. A square pyramid with a slant height of 26 and base edges of 20. The lateral area is 1040u^2.
TA=1040+(s^2). TA=1040+(20^2). TA=1040+400. TA=1440u^2.

Question 16

Lateral Area for a cylinder

Answer 16

LA=2(Pi)rh
Ex. A cylinder with a radius of 4 and a height of 7.
LA=2Pi(4)7. LA=8Pi(7). LA=56Pi

Question 17

Total area of a cylinder

Answer 17

TA= LA+2(Pi)r^2
Ex. A cylinder with a radius of 4 and a height of 7. LA=56Pi
TA=56Pi+2Pi(4)^2. TA=56Pi+2(16Pi). TA=56Pi+32Pi. TA=88Pi

Question 18

Lateral area of a cone

Answer 18

LA=(Pi)r(L) (L is the slant height)
Ex. A cone has a slant height of 30 and a radius of 13.
LA=Pi(13)(30). LA=390Pi

Question 19

Total area of a cone

Answer 19

TA= LA+(Pi)r^2
Ex. A cone has a slant height of 30 and a radius of 13. LA=390Pi
TA=390Pi+Pi(13)^2. TA=390Pi+Pi(169). TA= 559(Pi)u^2

Question 20

Area of a sphere

Answer 20

A=4(Pi)r^2

Question 21

Area of a hemisphere

Answer 21

A=2(Pi)r^2