Definition:Quadrantal Triangle

Definition

Let $\triangle ABC$ be a spherical triangle.

Let one of the sides of $\triangle ABC$ be a right angle: $\dfrac \pi 2$.

Then $\triangle ABC$ is known as a quadrantal (spherical) triangle.

Also see

• Definition:Right Spherical Triangle

Sources

• 1976: W.M. Smart: Textbook on Spherical Astronomy (6th ed.) ... (previous) ... (next): Chapter $\text I$. Spherical Trigonometry: $10$. Right-angled and quadrantal triangles.
• 1998: David Nelson: The Penguin Dictionary of Mathematics (2nd ed.) ... (previous) ... (next): quadrantal spherical triangle
• 1998: David Nelson: The Penguin Dictionary of Mathematics (2nd ed.) ... (previous) ... (next): spherical triangle
• 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): quadrantal spherical triangle
• 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): spherical triangle