Question

I'm having a hard time solving problems such as these because they don't have a base
http://prntscr.com/azp6du
http://prntscr.com/azp6le
I'm using this to answer the above and I'm also answering link two or problem two first
http://prntscr.com/azp6rv
For the second question all I've gotten so far is 360/8=45 divided by half is 22.5 for small triangle.

Do I use tan in this case to find the base and then double the base to find the side of the octagon that hasn't been made into a small triangle and then use tan again to find apothem?

Answer 1

@jhonyy9

Answer 2

If so, can I use SIMILAR mechanisms to solve for problem or link one?

Answer 3

@Kikuo are you here ?

Answer 4

Yep!

Answer 5

so there in this case bc. you know the radius not can using tan

Answer 6

so you know the central angle and the hypotenuse in case of this right triangle so what trgonometric function say that equal with op. or adj. divide hypotenuse ?

Answer 7

I didn't understand your first sentence, but yes to the rest.

Answer 8

not can using here in this exercise tangent bc. you know the hypotenuse and not the opposite side length - do you understand it now ?

Answer 9

and the tangent law say that equal opposite side divide adjacent side - yes ?

Answer 10

Oh I understand, so I have to use cosine instead.

Answer 11

yes exactly bc. what say the cosine law ?

Answer 12

Adj/hypotenuse

Answer 13

yes nice so can you use it now in this case

Answer 14

to find the length of apothem

Answer 15

yes ?

Answer 16

Yep! One second.

Answer 17

Sorry. Was answering a lady in biology. Alright! Doing it now.

Answer 18

np

Answer 19

9.741 for the answer!

Did 22.5cos=x/9 to get x(22.5cos)=9 to get x=9/22.5 and got 9/741

Answer 20

How do we find the perimeter to get the area now, though?

Answer 21

there i see radius length equal 10 not 9

Answer 22

It's link two haha.

Answer 23

ok i see it now so this is octagon not penthagon

Answer 24

Yes I did 360/8=45 and halved it

Answer 25

ok but how you have got this x result ?

Answer 26

so than cos 22,5 = x/9

x = ?

Answer 27

9.741

I showed work above but it showed my result as 9/741 instead of 9.741

Answer 28

cos22,5 = ? do you know it ?

Answer 29

so googled i got for cos22,5 = 0,92

than you know that 0,92 = x/9 so how you get from this the x ?

Answer 30

Is 9.741 incorrect?

Answer 31

multiplie both sides by 9 and so what will get for x = :

Answer 32

x=9*0,92 = ?

Answer 33

x= 8,28

Answer 34

I'l answer in just one second haha, but can you explain first why 9.741 is incorrect. Why can't we use 22.5?

Answer 35

22,5 is the measure of angle in radian

Answer 36

same with sin30 = 1/2 and not use in your calculi 30

Answer 37

or sin45 = sqrt2 /2

use in calculi sqrt2 /2 not 45

yes ?

Answer 38

so do you understand it now ?

Answer 39

22.5cos=x/9

Why was that setup incorrect?

Answer 40

sorry but i need to go - hope these wa ussefully

bye bye

what setup you think ?

Answer 41

this is right wrote

cos22,5 = x/9 and the result for x not is right what you have got

Answer 42

Alright. Thank you!

Answer 43

x=8,28 is right lenght what you need getting

Answer 44

was my pleasure

bye bye

Answer 45

Figure this one out? :)

Answer 46

@zepdrix

I'm having trouble with moving forward since I don't have the perimeter x(

Answer 47

Were you able to figure out the apothem?