Custom drapes are being fitted for a large circular window. The window has an 8 ft horizontal shelf with a 2 ft brace that sits in the frame. If the brace is extended upward, it would go through the center of the shelf and the circle.

What is the diameter of the window?

Diameter [tex]$=$[/tex] [tex]$\square$[/tex] feet



Answer :

To determine the diameter of the circular window, we will use the information about the horizontal shelf and the brace, which help us form a right-angled triangle. Here’s a step-by-step explanation:

1. Identify the given components:
- The length of the horizontal shelf is 8 feet.
- The length of the brace is 2 feet.

2. Understand the geometry formed:
- The horizontal shelf and the brace form a right-angled triangle with the center of the circle.
- To simplify, the horizontal shelf can be considered divided into two equal parts by the brace which goes through the center, making each part have a length of [tex]\( 4 \)[/tex] feet.

3. Recognize the right-angled triangle:
- In the right-angled triangle, one leg (half of the horizontal shelf) is 4 feet.
- The other leg (the brace) is 2 feet.
- The hypotenuse of this triangle is the radius of the circle.

4. Apply the Pythagorean theorem:
The Pythagorean theorem states that in a right-angled triangle, the square of the hypotenuse ([tex]\( c \)[/tex]) is equal to the sum of the squares of the other two sides ([tex]\( a \)[/tex] and [tex]\( b \)[/tex]):
[tex]\[ a^2 + b^2 = c^2 \][/tex]
Where [tex]\( a = 4 \)[/tex] feet and [tex]\( b = 2 \)[/tex] feet.

5. Calculate the radius of the circle ([tex]\( c \)[/tex]):
[tex]\[ 4^2 + 2^2 = c^2 \][/tex]
[tex]\[ 16 + 4 = c^2 \][/tex]
[tex]\[ c^2 = 20 \][/tex]
[tex]\[ c = \sqrt{20} \approx 4.47213595499958 \text{ feet} \][/tex]

6. Determine the diameter of the window:
The diameter ([tex]\( d \)[/tex]) is twice the radius:
[tex]\[ d = 2 \times c = 2 \times 4.47213595499958 \approx 8.94427190999916 \text{ feet} \][/tex]

So, the diameter of the window is approximately:
[tex]\[ \boxed{8.94427190999916} \text{ feet} \][/tex]