Question

how do you find the area of a trapezoid?

Answer 1

general formula
h=height
b1=bottom base length
b2=top base length
A = (1/2)*h*(b1+b2)

Answer 2

so I don't need to worry about the side length and degree that they gave me?

Answer 3

for area no as long as you have all the other information you need

Answer 4

I don't have the height but have a side length

Answer 5

set up right triangle by drawing line straight down from where side meets top

Answer 6

which angle did they give you, top or bottom?

Answer 7

they gave me bottom so instead of hte right angle being 90 it's 65 then the angle opposite is 90 and top is 25 the hypotenuse is 14in

Answer 8

ok to find height you have use trig
sin65 =opposite/hypotenuse = h/14
h = 14*sin65

Answer 9

which is about 12.7
now I just plug it in

Answer 10

A=.5(12.7(12+25))
A= about 235

Answer 11

thanks

Answer 12

good ;)

Answer 13

wait lol my teacher showed me how to do this next one but I forgot it

Answer 14

tanx=-1
given that 0 degrees is less than or equal to x which is less than or equal to 360 degrees

Answer 15

tanx = sinx/cosx
tanx = -1
so
sinx/cosx = -1
multiply cosx on both sides
sinx = -cosx
for what x on unit circle is sin opposite of cos

Answer 16

we are solving for x

Answer 17

thats what i am assuming

Answer 18

yes

Answer 19

do you have a unit circle?

Answer 20

this is for w/out calculator
if you are allowed to use calculator
you could enter arctan(-1)

Answer 21

I'm using a TI-83 a way old version of graphing calcs

Answer 22

and no unit circle

Answer 23

haha hey thats what i use
ok what do you get when you enter arctan(-1)

Answer 24

and exactly how am I supposed to enter arctan(-1)? lol

Answer 25

theres a tan^-1 above the tan button

Answer 26

the inverse of tan is = arctan(-1)?

Answer 27

yes sorry inverse tan is also called arctan

Answer 28

-45?

Answer 29

good but 0<x<360
-45 = 360-45

Answer 30

is there no value?

Answer 31

neg angle just refers to direction
315 degrees in positive direction is same as 45 degrees in negative direction
think of a circle

Answer 32

ok got it thanks:)

Answer 33

i see you