A bedroom wall is in the shape of a trapezoid that can be divided into a rectangle and a triangle.



Using the $45^{\circ}-45^{\circ}-90^{\circ}$ triangle theorem, find the missing dimension of the wall.


A6.5 ft
B$6.5 \sqrt{2} \text{ ft}$
C13 ft

Verified Answer :

  • The wall is modeled as a composite of a rectangle and a \(45^\circ-45^\circ-90^\circ\) triangle.
  • The legs of a \(45^\circ-45^\circ-90^\circ\) triangle are equal in length, denoted as \(x\), and the hypotenuse is \(x\sqrt{2}\).
  • Given the option \(6.5\sqrt{2}\), it follows that the leg length \(x\) is \(6.5 \text{ ft}\).
  • The "value of the wall" typically refers to the length of the slanted hypotenuse, which is \(\boxed{6.5\sqrt{2} \text{ ft}}\).

Explanation

  1. Analyze the geometry and the theorem

To understand the "value of the wall," we analyze the geometry of the wall modeled as a rectangle and a triangle. A trapezoidal wall can often be divided into a rectangular section and one or more triangular sections. The problem mentions the \(\mathbf{45^{\circ}-45^{\circ}-90^{\circ}}\) triangle theorem. In such a right-angled isosceles triangle with leg length \(x\), the hypotenuse (the slanted side) is given by \(x\sqrt{2}\). If the wall's triangular part has a height \(h = 6.5 \text{ ft}\) and is a \(45^{\circ}-45^{\circ}-90^{\circ}\) triangle, then the base of that triangle is also \(6.5 \text{ ft}\), and its slanted side (the hypotenuse) is \(6.5\sqrt{2} \text{ ft}\).

  1. Evaluate the options and identify the solution

Given the options:

A\(6.5 \text{ ft}\)
B\(6.5\sqrt{2} \text{ ft}\)
C\(13 \text{ ft}\)

The value \(6.5\) represents the leg of the triangle, while \(6.5\sqrt{2}\) represents the hypotenuse of the triangular part of the wall. In geometric modeling of a wall where a slanted side is present, the "value of the wall" typically refers to the length of that slanted side, which follows the \(x\sqrt{2}\) relationship. Therefore, the most standard identification for the slanted wall segment, given the theorem, is \(6.5\sqrt{2} \text{ ft}\).

  1. State the final answer

The value of the wall, based on the application of the \(45^{\circ}-45^{\circ}-90^{\circ}\) triangle theorem where the leg is \(6.5 \text{ ft}\), is the length of the slanted edge corresponding to the hypotenuse of the triangular section. Thus, the correct value is \(\boxed{6.5\sqrt{2} \text{ ft}}\).

Examples

This geometry concept is commonly used in construction and home renovation. For instance, when installing a slanted roof section or a decorative trapezoidal wall in a room, you need to calculate the precise length of the support beams (the hypotenuse) based on the height (the leg). By knowing that the height of the rectangular portion is \(6.5 \text{ ft}\) and the triangle's angle is \(45^\circ\), you can easily determine that the support beam must be exactly \(6.5 \times \sqrt{2} \approx 9.19 \text{ ft}\) to ensure the wall is perfectly square and structurally sound.