Question

please help me
with number one

Answer 1

what is number one?

Answer 2

that one

Answer 3

Since you know the length of the hypotenuse and the 30 degree angle you can use cosine to find the length of the adjacent side. Once you have the length of the adjacent side you can use the Pythagorean theorem (a^2 + b^2 = c^2) to find the length of the other side!

Answer 4

@ChristianGeek can you help me with it??

Answer 5

to work out the y side you need to put in your calculator
cos(30)

then you will get 0.86602540378443864676372317075294

you now have to multiply this by the length of the side we already have which is 20

so

0.86602540378443864676372317075294 * 20 = 17.32

now that is the length of the side y.

Answer 6

whoa thats alot of numbers

Answer 7

sorry i was copying and pasting i think you only need it to 2 decimal points you dont need that many numbers lol

Answer 8

26.45?

Answer 9

idk im confuse

Answer 10

@ChristianGeek you there??

Answer 11

what are you confused about

Answer 12

everything

Answer 13

ok have you learnt that you may need to use cos sin or tan to work out the length of a side on a triangle

Answer 14

wat does cos mean?

Answer 15

try having a read through this for maybe a better understanding
http://www.mathsisfun.com/algebra/trig-finding-side-right-triangle.html

Answer 16

@lilg132 ive had read for staraight 6 hours i dont think i wanna read at the moment

Answer 17

cos is a button on your calculator

Answer 18

so is sin and tan

Answer 19

oh

Answer 20

i really think you need to read that link for you to understand the basics it will be very difficult for me to explain otherwise

Answer 21

did i get number 3 right? i put this tan 60 = x/4

Answer 22

The cos of an angle is equal to the length of the adjacent side divided by the length of the hypotenuse, right? So start with:

\[\cos 30 = \frac{y}{20}\]\[20 cos 30 = y\]\[20 \frac{\sqrt{3}}{2} = y\]\[y = 10 \sqrt{3}\]
Now plug y into the Pythagorean theorem:

\[x^{2} + y^{2} = 20^{2}\]\[x^{2} + (10 \sqrt{3})^{2} = 400\]\[x^{2} + (100 \times 3) = 400\]\[x^{2} + 300 = 400\]\[x^{2} = 100\]\[x = 10\]
You can use a calculator to simplify y if you want.

Answer 23

no you do tan 60 which will give you a number
then you multiply this number with the length of the side you already have which is 4 that gives you the side

Answer 24

cos = cosine

Answer 25

Sorry about the delay...took me a while to type!