Question

Find the volume of a pyramid with a square base with dimensions 100 mm by 100 mm and height of 75 mm. Enter the numerical answer only.

Answer 1

I got 250,000 as an answer but I don't think it is right.

Answer 2

250,000 is correct

Answer 3

what about this question: Find the surface area of a cone with radius 30 in and slant height 50 in. Use 3.14 for pi. Enter the numerical answer only.

Answer 4

you find the area of the base

100*100 = 10,000

then you multiply this with the height

10,000*75 = 750,000

finally, you divide this by 3

750,000/3 = 250,000

Answer 5

what did you get?

Answer 6

i cant figure it out... i have like 4 problems i have no clue on what to do...

Answer 7

is the surface area 141371.67 and the volume 47123.89?

Answer 8

surface area of cone

SA = pi*r^2 + pi*r*s

r = radius
s = slant height

Answer 9

SA=pi*30^2 + pi*30*50
SA=7539.82

Answer 10

good

Answer 11

if you used 3.14 for pi, you would get 7,536

Answer 12

so 7,536 is your final answer

Answer 13

Then how would you solve for the volume?
V=1/3 (area of base) *(height)???

Answer 14

good, you have the correct formula

Answer 15

keep in mind that you need to find the height first

Answer 16

it's not the same as the slant height btw

Answer 17

so how would I do that?

Answer 18

hint:



h = height
r = radius
s = slant height

Answer 19

another hint

h^2 + r^2 = s^2

Answer 20

so h would be 40?

Answer 21

correct

Answer 22

so the volume would be 100480?

Answer 23

what is the area of the base

Answer 24

7536?

Answer 25

that was the overall surface area

Answer 26

ohhhh.....

Answer 27

the base is a circle with a radius of 30

Answer 28

so how would I go about solving this... because the formula for area is l*w

Answer 29

area of circle

A = pi*r^2

r = 30 in this case

Answer 30

so A=pi*30^2
A=2827.43

THEN....
V=1/3(area of base)(height)
V=1/3(2827.43)(40)
V=37699.11184???

Answer 31

remember you're using 3.14 for pi, so

pi*30^2 = 3.14*30^2 = 2826

Answer 32

so the area of the base is 2826

Answer 33

ohh i am using my pi button on my calculator

Answer 34

I only have 2 other problems that I am really confused on in this quiz:
1: What is the volume of a pyramid that has a base with an area of 81 square feet and a height of 4 feet? Enter the numerical answer only.
2: Find the radius of the base of a cone with volume equal to nr010-1.jpg in³ and height equal to 12 in. Use 3.14 for pi. Enter the numerical answer only.

Answer 35

that's ok, i was too until I realized they put in "Use 3.14 for pi."

Answer 36

okay

Answer 37

What is the volume of a pyramid that has a base with an area of 81 square feet and a height of 4 feet? Enter the numerical answer only.

Answer 38

Volume of Pyramid = (Area of base)*(height)/3

Answer 39

so i would do 81*4/3

Answer 40

which is 108?

Answer 41

correct

Answer 42

Find the radius of the base of a cone with volume equal to nr010-1.jpg in³ and height equal to 12 in. Use 3.14 for pi. Enter the numerical answer only.

Answer 43

what is nr010-1.jpg in³ all about??

Answer 44

144pi

Answer 45

ok

Answer 46

Volume of Cone = (area of base)*(height)/3 ... note: a cone is a special type of pyramid

Answer 47

Volume of Cone = (area of base)*(height)/3

Volume of Cone = (pi*r^2)*(height)/3

V = (pi*r^2)*(h)/3

144pi = (pi*r^2)*(12)/3

solve for r

Answer 48

hint: the pi terms will divide and cancel, so no need to worry about that

Answer 49

so i will have 144/12*3?

Answer 50

no

Answer 51

and then square root

Answer 52

144pi = (pi*r^2)*(12)/3

144 = (12r^2)/3

..
..
..

r = ??

Answer 53

oh wait, misread what you typed, yes you're on the right track

Answer 54

144*3

Answer 55

432/12

Answer 56

square root of 36

Answer 57

r =6

Answer 58

very good