Math Problem Statement

find the exact value of x

Solution

To find the exact value of xx in the given right triangle, let's analyze the information provided in the diagram:

Given Information:

  • The base of the right triangle is 100 m.
  • The height is xx m.
  • There are two angles inside the triangle: 4545^\circ and 3030^\circ.

Objective:

We need to find the exact value of xx.

Approach:

Step 1: Analyzing the triangle

There are two smaller triangles within the larger right triangle:

  1. A 45-45-90 triangle.
  2. A 30-60-90 triangle.

Since xx is the height of the large triangle and the common side for both smaller triangles, let's use trigonometric identities.

Step 2: Use the 45-45-90 Triangle to find part of the base

In the 45-45-90 triangle, the legs are equal. Thus, if we denote the length of the segment adjacent to 4545^\circ as yy (which is part of the 100 m base), we have: tan(45)=opposite (height)adjacent=xy\text{tan}(45^\circ) = \frac{\text{opposite (height)}}{\text{adjacent}} = \frac{x}{y} Since tan(45)=1\text{tan}(45^\circ) = 1: x=yx = y

This means that the segment of the base adjacent to the 4545^\circ angle is also xx m.

Step 3: Apply the 30-60-90 Triangle properties

In the 30-60-90 triangle:

  • The side opposite the 3030^\circ angle is half the hypotenuse.
  • The side opposite the 6060^\circ angle (which is xx) is 3/2\sqrt{3}/2 times the hypotenuse.

Let the segment of the base adjacent to the 3030^\circ angle be zz, and since the total base is 100 m: z+y=100z + y = 100 But since y=xy = x, we have: z+x=100z + x = 100 Now, using the 30-60-90 triangle: tan(30)=xz\text{tan}(30^\circ) = \frac{x}{z} We know that tan(30)=13\text{tan}(30^\circ) = \frac{1}{\sqrt{3}}, so: 13=xz\frac{1}{\sqrt{3}} = \frac{x}{z} z=x3z = x\sqrt{3} Substitute this into the equation z+x=100z + x = 100: x3+x=100x\sqrt{3} + x = 100 Factor out xx: x(3+1)=100x(\sqrt{3} + 1) = 100 Solve for xx: x=1003+1x = \frac{100}{\sqrt{3} + 1} To rationalize the denominator: x=100(31)(3+1)(31)=100(31)31=100(31)2x = \frac{100(\sqrt{3} - 1)}{(\sqrt{3} + 1)(\sqrt{3} - 1)} = \frac{100(\sqrt{3} - 1)}{3 - 1} = \frac{100(\sqrt{3} - 1)}{2} Simplifying: x=50(31) metersx = 50(\sqrt{3} - 1) \text{ meters}

Final Answer:

x=50(31) metersx = 50(\sqrt{3} - 1) \text{ meters}

Would you like any further details or have any questions?

Relative Questions:

  1. How can you verify the correctness of the calculated height xx using different trigonometric methods?
  2. What would happen to the value of xx if the base was increased or decreased?
  3. How can the properties of the 45-45-90 and 30-60-90 triangles be applied in other geometry problems?
  4. If the height xx were given, how could you find the length of the hypotenuse of the large triangle?
  5. What is the significance of rationalizing the denominator in the final expression for xx?

Tip:

When dealing with triangles involving special angles (like 3030^\circ, 4545^\circ, and 6060^\circ), always consider using their specific trigonometric ratios to simplify the problem-solving process.

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Math Problem Analysis

Mathematical Concepts

Trigonometry
Special triangles
Right triangle

Formulas

Trigonometric ratios (tan, sin, cos)

Theorems

Properties of 45-45-90 triangle
Properties of 30-60-90 triangle

Suitable Grade Level

Grades 10-12