a right triangle must have perpendicular lines.
a right triangle must have perpendicular lines.
which type of triangle must have perpendicular lines?
a right triangle
closely related and important geometrical concepts are perpendicular lines, meaning lines that form right angles at their point of intersection, and orthogonality, which is the property of forming right angles, usually applied to vectors. the presence of a right angle in a triangle is the defining factor for right triangles, making the right angle basic to trigonometry.









































section::::in elementary geometry.









































a rectangle is a quadrilateral with four right angles. a square has four right angles, in addition to equal-length sides.









































the pythagorean theorem states how to determine when a triangle is a right triangle.









































section::::symbols.
right angle
the euler line of an isosceles triangle is perpendicular to the triangle's base.









































the droz-farny line theorem concerns a property of two perpendicular lines intersecting at a triangle's orthocenter.









































harcourt's theorem concerns the relationship of line segments through a vertex and perpendicular to any line tangent to the triangle's incircle.









































section::::in polygons.:quadrilaterals.









































in a square or other rectangle, all pairs of adjacent sides are perpendicular. a right trapezoid is a trapezoid that has two pairs of adjacent sides that are perpendicular.
perpendicular