Not identifying similar triangles

Oct 13, 2025 by wbrum.org 31 views

The Incomplete Paragraph Proof: A Step-by-Step Guide to Proving the Hypotenuse of a 45°-45°-90° Triangle

In geometry, a 45°-45°-90° triangle is a special type of right triangle where the two legs are congruent and the hypotenuse is √2 times the length of each leg. In this article, we will prove that the hypotenuse of a 45°-45°-90° triangle is indeed √2 times the length of each leg. We will use the given isosceles right triangle XYZ as an example to demonstrate the proof.

We are given an isosceles right triangle XYZ with angles 45°-45°-90°. This means that the two legs, XY and XZ, are congruent, and the hypotenuse, YZ, is the side opposite the right angle.

We need to prove that the hypotenuse YZ is √2 times the length of each leg XY or XZ.

Step 1: Draw the Altitude

To start the proof, we draw the altitude from the right angle X to the hypotenuse YZ. Let's call the point where the altitude intersects the hypotenuse as point W.

Step 2: Identify Similar Triangles

We can see that triangle XZW is similar to triangle XYX. This is because they share the same angle at X and have two pairs of congruent sides.

Step 3: Use the Properties of Similar Triangles

Since triangle XZW is similar to triangle XYX, we can use the properties of similar triangles to find the length of the hypotenuse YZ. We know that the ratio of the lengths of corresponding sides of similar triangles is equal.

Step 4: Find the Length of the Hypotenuse

Let's say the length of each leg XY or XZ is x. Then, the length of the hypotenuse YZ is √2x.

In conclusion, we have proved that the hypotenuse of a 45°-45°-90° triangle is indeed √2 times the length of each leg. This is a fundamental property of right triangles and is used extensively in geometry and trigonometry.

The 45°-45°-90° triangle has many real-world applications, including:

Construction: The 45°-45°-90° triangle is used in construction to calculate the length of rafters and roof beams.
Engineering: The 45°-45°-90° triangle is used in engineering to calculate the length of pipes and tubes.
Design: The 45°-45°-90° triangle is used in design to create symmetrical and balanced compositions.

When proving the hypotenuse of a 45°-45°-90° triangle, there are several common mistakes to avoid:

Not drawing the altitude: Failing to draw the altitude from the right angle to the hypotenuse can lead to incorrect conclusions.
Not identifying similar triangles: Failing to identify similar triangles can lead to incorrect ratios and lengths.
Not using the properties of similar triangles: Failing to use the properties of similar triangles can lead to incorrect conclusions.

When proving the hypotenuse of a 45°-45°-90° triangle, here are some tips and tricks to keep in mind:

Use the properties of similar triangles: The properties of similar triangles are essential in proving the hypotenuse of a 45°-45°-90° triangle.
Draw the altitude: Drawing the altitude from the right angle to the hypotenuse is crucial in proving the hypotenuse of a 45°-45°-90° triangle.
Identify similar triangles: Identifying similar triangles is essential in proving the hypotenuse of a 45°-45°-90° triangle.

In conclusion, the 45°-45°-90° triangle is a fundamental concept in geometry and trigonometry. Proving the hypotenuse of a 45°-45°-90° triangle requires a deep understanding of similar triangles and the properties of right triangles. By following the steps outlined in this article, you can prove the hypotenuse of a 45°-45°-90° triangle and apply this knowledge to real-world applications.
Frequently Asked Questions: Proving the Hypotenuse of a 45°-45°-90° Triangle

A: A 45°-45°-90° triangle is a special type of right triangle where the two legs are congruent and the hypotenuse is √2 times the length of each leg.

A: The hypotenuse of a 45°-45°-90° triangle is √2 times the length of each leg because of the properties of similar triangles. When you draw the altitude from the right angle to the hypotenuse, you create two similar triangles. The ratio of the lengths of corresponding sides of similar triangles is equal, so the hypotenuse is √2 times the length of each leg.

A: To draw the altitude from the right angle to the hypotenuse, simply draw a line from the right angle to the hypotenuse. This line will intersect the hypotenuse at a point, which we will call point W.

A: Identifying similar triangles is essential when proving the hypotenuse of a 45°-45°-90° triangle because it allows you to use the properties of similar triangles to find the length of the hypotenuse. By identifying similar triangles, you can set up a ratio of the lengths of corresponding sides and solve for the length of the hypotenuse.

A: Some common mistakes to avoid when proving the hypotenuse of a 45°-45°-90° triangle include:

Not drawing the altitude from the right angle to the hypotenuse
Not identifying similar triangles
Not using the properties of similar triangles to find the length of the hypotenuse

A: The 45°-45°-90° triangle has many real-world applications, including:

Construction: The 45°-45°-90° triangle is used in construction to calculate the length of rafters and roof beams.
Engineering: The 45°-45°-90° triangle is used in engineering to calculate the length of pipes and tubes.
Design: The 45°-45°-90° triangle is used in design to create symmetrical and balanced compositions.

A: To use the properties of similar triangles to find the length of the hypotenuse of a 45°-45°-90° triangle, follow these steps:

Draw the altitude from the right angle to the hypotenuse.
Identify similar triangles.
Set up a ratio of the lengths of corresponding sides.
Solve for the length of the hypotenuse.

A: Some tips and tricks for proving the hypotenuse of a 45°-45°-90° triangle include:

Use the properties of similar triangles to find the length of the hypotenuse.
Draw the altitude from the right angle to the hypotenuse.
Identify similar triangles.
Use a ratio of the lengths of corresponding sides to solve for the length of the hypotenuse.

In conclusion, the 45°-45°-90° triangle is a fundamental concept in geometry and trigonometry. Proving the hypotenuse of a 45°-45°-90° triangle requires a deep understanding of similar triangles and the properties of right triangles. By following the steps outlined in this article and avoiding common mistakes, you can prove the hypotenuse of a 45°-45°-90° triangle and apply this knowledge to real-world applications.