mathinschool.com
numbers and algebraic expressions
logic, sets, intervals
absolute value
function and its properties
linear function
quadratic function
polynomials
rational function
exponential function
logarithm
number sequences
limits of sequences and functions
derivative and integral of functions
trigonometry
plane geometry
analytic geometry
solid geometry
combinatorics
probability
elements of statistics
kropki game

Radius: R = a/2sinα. a - lenght of any side of triangle, α - the angle opposite this side. R = abc/P. a, b, c - lenghts of side of the triangle, P - area of the triangle. If one of the sides of the triangle is the diameter then the triangle inscribed in a circle is right. For the triangle inscribed in a circle, center of this circle get draw an axes of symmetry for the sides of triangle.