A rectangle has sides of length [tex]\sqrt{3} + 1[/tex] and [tex]\sqrt{3} - 1[/tex]. Find the perimeter, the area, and the length of a diagonal, expressing each answer as a surd in its simplest form.



Answer :

Sure, let's solve the problem step-by-step. We will find the perimeter, the area, and the diagonal length of the given rectangle.

### Given Data:
The sides of the rectangle are:
- Side 1: [tex]\(\sqrt{3} + 1\)[/tex]
- Side 2: [tex]\(\sqrt{3} - 1\)[/tex]

### Step-by-Step Solution:

1. Perimeter of the Rectangle:

The perimeter [tex]\(P\)[/tex] of a rectangle is calculated by the formula:
[tex]\[ P = 2 \times (\text{Length} + \text{Breadth}) \][/tex]

Here, we have:
[tex]\[ P = 2 \times ((\sqrt{3} + 1) + (\sqrt{3} - 1)) \][/tex]

Simplifying inside the parentheses:
[tex]\[ (\sqrt{3} + 1) + (\sqrt{3} - 1) = \sqrt{3} + \sqrt{3} + 1 - 1 = 2\sqrt{3} \][/tex]

Therefore, the perimeter is:
[tex]\[ P = 2 \times 2\sqrt{3} = 4\sqrt{3} \][/tex]

2. Area of the Rectangle:

The area [tex]\(A\)[/tex] of a rectangle is calculated by the formula:
[tex]\[ A = \text{Length} \times \text{Breadth} \][/tex]

Here, the area [tex]\(A\)[/tex] will be:
[tex]\[ A = (\sqrt{3} + 1) \times (\sqrt{3} - 1) \][/tex]

We can use the difference of squares formula: [tex]\((a + b)(a - b) = a^2 - b^2\)[/tex], where [tex]\(a = \sqrt{3}\)[/tex] and [tex]\(b = 1\)[/tex]:
[tex]\[ (\sqrt{3})^2 - (1)^2 = 3 - 1 = 2 \][/tex]

Therefore, the area is:
[tex]\[ A = 2 \][/tex]

3. Length of the Diagonal:

The length of the diagonal [tex]\(d\)[/tex] of a rectangle can be found using the Pythagorean theorem:
[tex]\[ d = \sqrt{(\text{Length})^2 + (\text{Breadth})^2} \][/tex]

Substituting the side lengths:
[tex]\[ d = \sqrt{(\sqrt{3} + 1)^2 + (\sqrt{3} - 1)^2} \][/tex]

Expanding both squares:
[tex]\[ (\sqrt{3} + 1)^2 = (\sqrt{3})^2 + 2(\sqrt{3})(1) + 1^2 = 3 + 2\sqrt{3} + 1 = 4 + 2\sqrt{3} \][/tex]
[tex]\[ (\sqrt{3} - 1)^2 = (\sqrt{3})^2 - 2(\sqrt{3})(1) + 1^2 = 3 - 2\sqrt{3} + 1 = 4 - 2\sqrt{3} \][/tex]

Adding these results:
[tex]\[ 4 + 2\sqrt{3} + 4 - 2\sqrt{3} = 8 \][/tex]

Thus, the length of the diagonal is:
[tex]\[ d = \sqrt{8} = 2\sqrt{2} \][/tex]

### Summary of Results:
- The perimeter of the rectangle is: [tex]\(4\sqrt{3}\)[/tex]
- The area of the rectangle is: 2
- The length of the diagonal is: [tex]\(2\sqrt{2}\)[/tex]