# Table of Contents

**The concept and basic properties of right triangles**

The definition of a right triangle and the name of its sides

The criteria for a right triangle

The congruence of right triangles

The similarity of right triangles

The area of a right triangle. Formulae

Proportional line segments in a right triangle

Squares inscribed into a right triangle

**The sides of the right triangle and their properties**

Converse of the Pythagorean theorem

Properties of the sides of a right triangle

**The angles of the right triangle and their properties**

Properties of the angles of a right triangle

The angle between the angle bisector and the height

**Height in a right triangle**

The height of a right triangle and similar triangles

Formulas of the height of a right triangle

**Median in a right triangle**

The median drawn to the hypotenuse. Properties

Formulas of the median of a right triangle

**Circumscribed and inscribed circle and right triangle**

The radius of a circle inscribed in a right triangle. Formulas

Radius of the circumscribed circle

Thales’ theorem. Statement on the inscribed angle subtended by the diameter of the circle

**The right isosceles triangle**

The definition of a right isosceles triangle and its properties