Hello !

We have a square - find alpha ?

Printable View

- June 19th 2011, 03:54 AMyehoramHow much is alpha?
Hello !

We have a square - find alpha ? - June 19th 2011, 04:04 AMPlatoRe: How much is alpha?
There is not enough information to answer.

There must be more given. What else do you know? - June 19th 2011, 04:16 AMyehoramRe: How much is alpha?
- June 19th 2011, 04:59 AMArchie MeadeRe: How much is alpha?
Rotate triangle AEB about B, until A rests on C.

Label the new position of "E" as "G".

Draw a line from E to G.

Angle EBG is 90 degrees.

Angles BEG and BGE are 45 degrees.

Use Pythagoras' Theorem to calculate |EG|

Triangle ECG now has all 3 sides (if you let |AE|=1, |EB|=2, |EC|=3)

and you rearrange the law of cosines to calculate "alpha-45" degrees

and therefore "alpha". - June 19th 2011, 05:08 AMyehoramRe: How much is alpha?