Question

what type of right triangle is this if:
a=90, b=y+40, c=3y-10

Answer 1

im assuming a,b,and c are degrees. then b+c=90

Answer 2

Well, no they are all side measurements

Answer 3

and also, i am figuring for y.

Answer 4

is a the hypotenuse?

Answer 5

no, c is.

Answer 6

then c^2 - b^2 = a^2

Answer 7

do that and the quadratic formula to solve for y

Answer 8

Yes, the pythagorean theorem... and to tell the truth i have absolutely no idea what that means

Answer 9

what does "that" refer to?

Answer 10

"that" refers to do that and the quadratic formula to solve for y

Answer 11

just plug in everything you know into the pythagorean theorem. then rearrange what you get so that you can use the quadratic formula.

Answer 12

(3y-10)^2 - (y+40)^2 = 90^2

Answer 13

well.... i did the same thing except i used a squared plus b squared equals c squared

Answer 14

that works too

Answer 15

now just rearrange it all so that everything is on one side of the equation

Answer 16

okay but i dont come up with y being a perfect square.

Answer 17

i tried this:

a=90,b=y+40,c=3y-10
a2+b2=c2 squared=2
so
902+(y+40)2=(3y-10)2
8100+y2+1600=3y2+100
9700+y2=3y2+100
9600+y2=3y2=2y2+100
9600=2y2
4800=y2

Answer 18

you squared incorrectly. (y+40)^2 is y^2+80y+1600. same with (3y-10)^2, that was squared incorrectly too

Answer 19

how do you get 80y?

Answer 20

use the foil method.

Answer 21

please elaborate....

Answer 22

hmmm. write out (y+40)x(y+40). then distribute.
so it becomes y*y + y*40 + 40*y + 40*40

Answer 23

ooooohhhhh!!!! okay genius.... (in a good way) thank you so much!

Answer 24

lol no problem. by the way, the answer isn't a whole number.

Answer 25

I'm in seventh grade honors and lets just say my teacher isnt exactly very to the point. and oh are you serious? so its not a perfect square?

Answer 26

nope =(

Answer 27

ohhh jeez. i was having a hard time the whole time because i thought it HAD to be a perfect square... :) whoops.

Answer 28

lol.