To find the missing length of a triangle, you’ll need to make use of the Pythagorean theorem. This states that for a triangle with side lengths a, b and c, a^2 + b^2 = c^2. When you know two side lengths of a triangle (let’s call them sides a and b), you can use the following equation to calculate the third side (c): c = √(a^2 + b^2).

For example, if you have a right triangle with side lengths of 9 and 12, then the missing length of the hypotenuse is c = √(9^2 + 12^2) = 15. This means that the missing length of the triangle is 15.

To apply this equation to finding the missing length of a non-right triangle, you need to know the lengths of two sides and the measure of one of the angles (other than the right angle). Knowing two sides of a triangle with the measure of one of the angles allows you to use the Law of Cosines, which states that:

c^2 = a^2 + b^2 – 2abcos(C).

The angle C in this equation is the angle whose measure you know, and the sides a and b are the lengths of the two sides you know. Once you have this equation, you can rearrange it to calculate the missing side, which is equal to c:

c = √(a^2 + b^2 – 2abcos(C)).

For example, let’s say you have a triangle with side lengths of 5 and 6 and an angle ∠C, whose measure is 30°. You can calculate the missing side length (side c), using c = √(5^2 + 6^2 – 2*5*6cos(30°)) = 7.

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So, in summary, the way to find the missing length of a triangle is to use either the Pythagorean theorem (if you have a right triangle) or the Law of Cosines (if you have a non-right triangle).

FAQ

- 1 What are the 3 formulas for the area of a triangle?
- 2 What is the length of third side of each triangle?
- 3 What are the 3 triangles called?
- 4 What is a triangle answer?
- 5 How many triangles are there name?
- 6 What kind of triangle is never wrong?
- 7 Is any 3 sided polygon a triangle?
- 8 Which triangle has no equal side?

## What are the 3 formulas for the area of a triangle?

The three most common formulas for the area of a triangle are based on the lengths of the sides of the triangle.

The first is Heron’s Formula:

A=√(s(s−a)(s−b)(s−c)),

where s is the semiperimeter of the triangle, that is,

s=(a+b+c)/2.

The second is the Triangle Inequality Theorem, which states that the sum of the lengths of any two sides of a triangle must be greater than the length of the third side. This formula can be written as:

A≥bh/2.

The last common formula is the Radius of the Inscribed Circle, sometimes called the Inradius:

r=A/s.

## What is the length of third side of each triangle?

The third side of a triangle is the side that is not adjacent to either of the other two sides. The length of the third side can be found using the Pythagorean Theorem.

## What are the 3 triangles called?

There are three types of triangles: equilateral, isosceles, and scalene.

An equilateral triangle has all three sides the same length, and all three angles are also equal, making it a symmetrical shape.

An isosceles triangle has two sides that are the same length, and two angles that are the same. The third side and angle will be different.

A scalene triangle has all three sides and angles that are different.

## What is a triangle answer?

A triangle answer is a response to a question that is either unclear or difficult to answer. It is often used as a way to stall for time or to avoid answering the question directly. In some cases, a triangle answer may be used to deflect blame or responsibility away from the person being asked the question.

## How many triangles are there name?

There are an infinite number of triangles that one could name.

## What kind of triangle is never wrong?

There’s no such thing as a “triangle that’s never wrong”! Depending on how you measure it, any given triangle can have different angles and sides. So a triangle could be classified as “right” if it has two 90 degree angles, but “obtuse” if it has just one 90 degree angle.

It all depends on your perspective!.

## Is any 3 sided polygon a triangle?

No, not every three-sided polygon is a triangle. In geometry, a triangle is a three-sided polygon with three angles that are all less than 180 degrees. This is what differentiates a triangle from other three-sided polygons.

## Which triangle has no equal side?

An isosceles triangle has two equal sides. An equilateral triangle has three equal sides. A scalene triangle has no equal sides.