45-45-90 triangles are a unique type of isosceles right triangle that presents fascinating properties and applications in geometry. Understanding these triangles can greatly enhance your mathematical skills and problem-solving abilities. In this article, we'll dive into the features of 45-45-90 triangles, how to solve problems involving them, and provide a comprehensive worksheet to test your understanding. ๐๐
What is a 45-45-90 Triangle?
A 45-45-90 triangle is a special type of right triangle where the angles measure 45 degrees, 45 degrees, and 90 degrees. The unique quality of this triangle lies in its side lengths, which have a specific relationship.
Properties of 45-45-90 Triangles
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Isosceles Nature: Since the two angles are equal, the sides opposite those angles are also equal. If we denote the lengths of the legs as ( x ), then:
- Leg 1 = ( x )
- Leg 2 = ( x )
- Hypotenuse = ( x\sqrt{2} )
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Pythagorean Theorem: The sides of 45-45-90 triangles are often computed using the Pythagorean theorem:
[ a^2 + b^2 = c^2 ]
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Applications: These triangles appear in various fields such as architecture, computer graphics, and engineering. Their properties make them essential for calculating dimensions and angles effectively.
Visual Representation
Before proceeding to calculations, it's essential to visualize a 45-45-90 triangle:
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x | \ xโ2
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x
Key Formulas
Here are some crucial formulas when working with 45-45-90 triangles:
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Leg Length: If the length of each leg is ( x ), the hypotenuse ( h ) can be calculated as:
[ h = x\sqrt{2} ]
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Finding the Leg from the Hypotenuse: Conversely, if the hypotenuse ( h ) is known:
[ x = \frac{h}{\sqrt{2}} ]
Example Problems
Let's put our knowledge to the test with a couple of example problems:
Example 1: Given the Leg Length
Problem: If one leg of a 45-45-90 triangle is 5 cm, find the length of the hypotenuse.
Solution:
Using the formula:
[ h = x\sqrt{2} = 5\sqrt{2} \approx 7.07 \text{ cm} ]
Example 2: Given the Hypotenuse Length
Problem: If the hypotenuse of a 45-45-90 triangle is 14 cm, what is the length of each leg?
Solution:
Using the formula:
[ x = \frac{h}{\sqrt{2}} = \frac{14}{\sqrt{2}} = 7\sqrt{2} \approx 9.90 \text{ cm} ]
Worksheet: Master Geometry Concepts
To reinforce your understanding, below is a worksheet designed to test your knowledge of 45-45-90 triangles. Solve the problems and check your answers at the end! ๐
<table> <tr> <th>Problem</th> <th>Type</th> </tr> <tr> <td>1. If one leg is 8 cm, find the hypotenuse.</td> <td>Find Hypotenuse</td> </tr> <tr> <td>2. If the hypotenuse is 10 cm, find the length of each leg.</td> <td>Find Leg Length</td> </tr> <tr> <td>3. Calculate the hypotenuse when each leg is 12 cm.</td> <td>Find Hypotenuse</td> </tr> <tr> <td>4. If the hypotenuse measures 20 cm, what are the leg lengths?</td> <td>Find Leg Length</td> </tr> <tr> <td>5. A triangular garden has a 45-45-90 shape with one leg measuring 6 m. What is the total perimeter?</td> <td>Perimeter Calculation</td> </tr> </table>
Important Notes
"Always remember the unique relationships between the sides of a 45-45-90 triangle. These shortcuts can save you time on tests and in practical applications!" ๐
Tips for Success
- Practice Regularly: Frequent practice can help solidify your understanding of triangle properties.
- Use Diagrams: Visual aids can enhance your comprehension of geometric principles.
- Explore Real-Life Applications: Look for examples in architecture or nature to see 45-45-90 triangles in action.
Understanding 45-45-90 triangles not only strengthens your geometry skills but also lays the groundwork for more complex mathematical concepts. With practice and application, you can master this essential aspect of geometry!