Obtuse Triangle

Definition

An obtuse triangle is a triangle in which one of the angles is greater than 90 degrees. This type of triangle is particularly relevant in the context of non-right triangles and the application of the Law of Sines, as the presence of an obtuse angle affects the calculations and relationships between the sides and angles of the triangle.

5 Must Know Facts For Your Next Test

1. In an obtuse triangle, the angle greater than 90 degrees is called the obtuse angle.
2. The presence of an obtuse angle in a triangle affects the application of the Law of Sines, as the sine function behaves differently for angles greater than 90 degrees.
3. Obtuse triangles are often encountered in real-world applications, such as in surveying, navigation, and architectural design.
4. The sum of the angles in an obtuse triangle is always greater than 180 degrees.
5. Obtuse triangles can be classified based on the relationships between their sides, such as isosceles obtuse triangles or scalene obtuse triangles.

Review Questions

• Explain how the presence of an obtuse angle in a triangle affects the application of the Law of Sines.
  • The presence of an obtuse angle in a triangle affects the application of the Law of Sines because the sine function behaves differently for angles greater than 90 degrees. In an obtuse triangle, the sine of the obtuse angle will be negative, which means that the Law of Sines equation must be adjusted accordingly. This is an important consideration when solving problems involving non-right triangles and the Law of Sines.
• Describe the relationship between the angles in an obtuse triangle and the sum of those angles.
  • In an obtuse triangle, the sum of the three angles is always greater than 180 degrees. This is because one of the angles is greater than 90 degrees, which means that the other two angles must be less than 90 degrees to maintain the triangle's overall structure. Understanding this relationship between the angles in an obtuse triangle is crucial when applying the Law of Sines and other trigonometric concepts to solve problems involving non-right triangles.
• Analyze the different types of obtuse triangles and how their side relationships might affect the application of the Law of Sines.
  • Obtuse triangles can be classified based on the relationships between their sides, such as isosceles obtuse triangles or scalene obtuse triangles. The side relationships in an obtuse triangle can impact the application of the Law of Sines, as the ratios between the sides and the sine of the angles will vary depending on the triangle's classification. For example, in an isosceles obtuse triangle, the Law of Sines may be applied differently than in a scalene obtuse triangle due to the symmetry of the sides and the resulting angle relationships. Recognizing these nuances is essential when solving problems involving the Law of Sines and non-right triangles.

Related terms

Acute Triangle: A triangle in which all three angles are less than 90 degrees.

Right Triangle: A triangle in which one of the angles is exactly 90 degrees.

Angle of Elevation:

The angle between the horizontal line of sight and the line of sight to an object above the observer.