- In geometry and trigonometry, a right angle is an angle of exactly 90 degrees or đ/2 radians corresponding to a quarter turn. If a ray is placed so that its endpoint is on a line and the adjacent angles are equal, then they are right angles. The term is a calque of Latin angulus rectus; here rectus means “upright”, referring to the vertical perpendicular to a horizontal base line.
- The Phenomenology of Spirit (Wikipedia)
The Phenomenology of Spirit (German: Phänomenologie des Geistes) is the most widely-discussed philosophical work of Georg Wilhelm Friedrich Hegel; its German title can be translated as either The Phenomenology of Spirit or The Phenomenology of Mind. Hegel described the work, published in 1807, as an “exposition of the coming to be of knowledge”. This is explicated through a necessary self-origination and dissolution of “the various shapes of spirit as stations on the way through which spirit becomes pure knowledge”.
