how do you find an angle on the coordinate plane without a protractor or a compass

Question

amistre64 · Answer

well, since its a corrdinate plane ... do some trig with a calculator

anonymous · Answer

idk how

amistre64 · Answer

for a given coord (x,y); tan(angle) = y/x   and other identities are similar if the distance fromthe origin can be detemrined

amistre64 · Answer

|dw:1396407533949:dw|

sin(a) = y/r
cos(a) = x/r
tan(a) = y/x

and the inverses are functions on a calculator as well.  if its a simple x,y there are things called special triangles that you can put to memory for comparison

anonymous · Answer

yes my teacher told us you can use special right triangles but she never told us how

amistre64 · Answer

a triangle scales ....

so if you know the leg lengths ,,,, you can compare that to the specials to see what fits.

amistre64 · Answer

|dw:1396407746101:dw|

and a 45 should be kindergarten work