Question

A lamppost casts a shadow 44 feet long. The angle measure of the shadow is 33°.


© 2011 Jupiter Images Corporation

How tall is the lamppost, rounded to the nearest tenth of a foot? Type the numeric answer only in the box below.

Numerical An

Answer 1

hint:

tan(angle) = opposite/adjacent

tan(33) = x/44

Answer 2

confused

Answer 3

x/44?

Answer 4

the opposite side is x and the adjacent side is 44

the goal now is to solve for x

what do you get when you do this?

Answer 5

divide?

Answer 6

you're dividing some unknown x by 44

so you need to undo this to isolate x

Answer 7

how do i isolate X

Answer 8

say you had

a = x/5

You would multiply both sides by 5 to get

5a = x

x = 5a

Answer 9

ok so in this situation x= 44x

Answer 10

no, you want to isolate x (or get x all by itself)

Answer 11

tan(33) = x/44

what can you do to move that 44 over?

Answer 12

u multiply both sides by 33?

Answer 13

no, you multiply both sides by 44

Answer 14

ok so 33 mulitiplied by 44?

Answer 15

not quite, it's tan(33) and not just 33

Answer 16

ok so how do i get the asnwer

Answer 17

tan(33) = x/44

44*tan(33) = x

x = 44*tan(33)

Now use a calculator to evaluate 44*tan(33)

Answer 18

i dont think i have tan on my calculator

Answer 19

what calculator do you have?

Answer 20

its on my computer just the computer one
i dont actually have one

Answer 21

alright, then you can use wolfram alpha

http://www.wolframalpha.com/input/?i=44*tan%2833+degrees%29

Answer 22

the answer is where you see "result" on that page

Answer 23

of course, you'll have to round to the nearest tenth

Answer 24

and that is how i get the answer? and it is 28.57

Answer 25

yes or you can type 44*tan(33 degrees) into google and google will use its calculator to get the answer 28.5739341006904

which rounds to 28.6

Answer 26

if you want to download a calculator to replace the windows default calculator (which I strongly recommend you do), I suggest you get this calculator

http://www.graphcalc.com/

It's basically a graphing calculator and supports sin, cos, tan, logs, exponents, etc

Answer 27

ok thank you!!!!!

Answer 28

yw