Pythagorean theorem (Wikipedia)
In mathematics, the Pythagorean theorem or Pythagoras’ theorem is a fundamental relation in Euclidean geometry between the three sides of a right triangle. It states that the area of the square whose side is the hypotenuse (the side opposite the right angle) is equal to the sum of the areas of the squares on the other two sides.- Right angle (Wikipedia)
In geometry and trigonometry, a right angle is an angle of exactly 90 degrees or 𝜋/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.
Frankly, I did not get full satisfaction from this interview.
Vladimir Putin
- Right triangle (Wikipedia)
A right triangle or right-angled triangle, sometimes called an orthogonal triangle or rectangular triangle, is a triangle in which two sides are perpendicular forming a right angle (1⁄4 turn or 90 degrees).