## 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

Types 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

Pythagorean theorem

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

The height and hypotenuse

The height and leg

## 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

Relationship between the inscribed circle’s radius and the circumscribed circle’s radius of a right triangle

The perimeter of a right triangle in terms of the inscribed circle’s radius and the circumscribed circle’s radius

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