## How do you find the sine of an obtuse triangle?

There, angle ABC is obtuse. But the sine of an obtuse angle is the same as the sine of its supplement. That means sin ABC is the same as sin ABD, that is, they both equal h/c. Likewise, it doesn’t matter whether angle C is acute or obtuse, sin C = h/b in any case.

## What is the rule for obtuse triangle?

A triangle whose any one of the angles is an obtuse angle or more than 90°, then it is called an obtuse-angled triangle or obtuse triangle. The sum of the interior angles of the obtuse triangle is equal to 180° only. This means the angle sum property for any triangle remains the same.

**Does SSA work for obtuse triangles?**

Indeed, SSA is incorrect if the given angle is acute, because the given criteria can produce two different possible triangles. However, if the given angle is right or obtuse, only one triangle can be produced, in which case SSA is a legitimate congruence theorem.

### Do obtuse triangles add up to 180?

Obtuse Triangle Definition An obtuse triangle is one that has an angle greater than 90°. Because all the angles in a triangle add up to 180°, the other two angles have to be acute (less than 90°). It’s impossible for a triangle to have more than one obtuse angle.

### Why is the sine of an obtuse angle negative?

The cosine of an obtuse angle is negative because of the range of the cosine function which is between 1 and -1. Therefore, when the cosine function completes its half cycle, it is at the middle of 1 and -1, that is 0.

**What are the properties of an obtuse triangle?**

Properties of Obtuse-Angled Triangles

- Property 1: The longest side of a triangle is the side opposite to the obtuse angle.
- Property 2: A triangle can only have one obtuse angle.
- Property 3: The sum of the other two angles in an obtuse triangle is always smaller than 90°.

## Why AAA criteria is not possible?

Knowing only angle-angle-angle (AAA) does not work because it can produce similar but not congruent triangles. When you’re trying to determine if two triangles are congruent, there are 4 shortcuts that will work. Because there are 6 corresponding parts 3 angles and 3 sides, you don’t need to know all of them.

## Which of the following measurement is for an obtuse angle?

An obtuse angle is an angle that measures more than 90 degrees and less than 180 degrees.

**What triangle does not add up to 180 degrees?**

The elliptic (or elliptical) geometry is generalization (by Felix Klein, 1872) of original spherical geometry or Riemannian geometry (Bernhard Riemann, 1854/1867). For example, the sum of the interior angles of a Poincare triangle is always less than 180 deg.

### Is obtuse angle positive or negative?

negative

The cosine of an obtuse angle is negative because of the range of the cosine function which is between 1 and -1.

### How do you find the angle of an obtuse angle?

To find if a triangle is obtuse, we can look at the angles mentioned. If one angle is greater than 90° and the other two angles are lesser along with their sum being lesser than 90°, we can say that the triangle is an obtuse triangle. For example, ΔABC has these angle measures ∠A = 120°, ∠A = 40°, ∠A = 20°.

**Is aas the same as SAA?**

– ASA and AAS are two postulates that help us determine if two triangles are congruent. ASA stands for “Angle, Side, Angle”, while AAS means “Angle, Angle, Side”. Two figures are congruent if they are of the same shape and size. In other words, two congruent figures are one and the same figure, in two different places.