# Find Length X in Triangle: Learn How to Calculate It

• MHB
• ketanco
In summary, the length x is being asked and FH and HC are both perpendicular. The answer is 5, but it is not clear how to obtain it. Klaas provides a hint to look for similar triangles, specifically ones that share two angles. This leads to the equation x = 4 * CF / BF.
ketanco
what is the length x? (FH and HC perpendicular too, which I missed to write)
I am totally stuck can not make any progress on this question. Answer should be 5. I don't know how to obtain it

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ketanco said:
FH and HC perpendicular too
Does that mean that angleCHF = 90?
AB = 9 and EF = 4?

Not important but why is there no point G (you jumped from F to H!)

ketanco said:
what is the length x? (FH and HC perpendicular too, which I missed to write)
I am totally stuck can not make any progress on this question. Answer should be 5. I don't know how to obtain it

Hint: Which triangles are similar to each other?
(Two triangles are similar if they have 2 angles in common.)

Once you get Klaas' hint, you should "see" that x = 4 * CF / BF

## 1. What is the formula for finding the missing length in a triangle?

The formula for finding the missing length in a triangle is the Pythagorean theorem, which states that in a right triangle, the square of the length of the hypotenuse (the side opposite the right angle) is equal to the sum of the squares of the other two sides.

## 2. How do I label the sides of a triangle for the calculation?

The sides of a triangle are typically labeled as A, B, and C, with the side opposite angle A being labeled as a, the side opposite angle B being labeled as b, and the side opposite angle C being labeled as c. It is important to label the sides correctly to ensure the correct calculation.

## 3. Can the Pythagorean theorem be used for all types of triangles?

No, the Pythagorean theorem can only be used for right triangles, where one of the angles is a 90-degree angle. For other types of triangles, different formulas and methods must be used to find the missing length.

## 4. Are there any other methods for finding the missing length in a triangle?

Yes, there are other methods for finding the missing length in a triangle. These include using trigonometric ratios (such as sine, cosine, and tangent) or using the Law of Cosines and Law of Sines, which are useful for solving non-right triangles.

## 5. How can I apply this knowledge to real-life situations?

The ability to find missing lengths in triangles is useful in a variety of real-life situations, such as in construction, engineering, and navigation. For example, knowing how to calculate the length of a ladder needed to reach a certain height on a building, or the distance between two points on a map, requires an understanding of triangle length calculations.

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