Identity ○꠹｜appendage｜___｜20260628174208-01-•

Visual proof of the Pythagorean identity: for any angle $\theta$, the point $(x,y)=(\cos \theta ,\sin \theta )$ lies on the unit circle, which satisfies the equation $x^2+y^2=1$. Thus, ${\cos }^2\theta +{\sin }^2\theta =1$.

(echo:: @ ᯤ)