Jace ordered a banner in the shape of a parallelogram from a print shop.

Heron's formula: Area [tex]\(A = \sqrt{s(s-a)(s-b)(s-c)}\)[/tex]

The print shop charges [tex]$1.10 per square foot for banners of any shape and size. What is the approximate cost of the banner before tax?

A. $[/tex]41.95
B. [tex]$46.14
C. $[/tex]83.90
D. $92.30



Answer :

Alright, let's solve this step-by-step to determine the approximate cost for the banner.

### Step 1: Determine the dimensions of the parallelogram
Jace ordered a banner with the following dimensions:
- [tex]\(a = 7\)[/tex] feet
- [tex]\(b = 8\)[/tex] feet
- [tex]\(c = 9\)[/tex] feet

### Step 2: Calculate the semi-perimeter
The semi-perimeter [tex]\(s\)[/tex] of the parallelogram is calculated by adding the lengths of the sides and dividing by 2:

[tex]\[ s = \frac{a + b + c}{2} \][/tex]

Substituting the given values:

[tex]\[ s = \frac{7 + 8 + 9}{2} \][/tex]
[tex]\[ s = \frac{24}{2} \][/tex]
[tex]\[ s = 12 \text{ feet} \][/tex]

### Step 3: Calculate the area using Heron's formula
Heron's formula for the area of a triangle is given by:

[tex]\[ \text{Area} = \sqrt{s(s-a)(s-b)(s-c)} \][/tex]

Substituting the semi-perimeter and side lengths:

[tex]\[ \text{Area} = \sqrt{12 \times (12 - 7) \times (12 - 8) \times (12 - 9)} \][/tex]
[tex]\[ \text{Area} = \sqrt{12 \times 5 \times 4 \times 3} \][/tex]
[tex]\[ \text{Area} = \sqrt{720} \][/tex]
[tex]\[ \text{Area} \approx 26.83 \text{ square feet} \][/tex]

### Step 4: Calculate the cost of the banner
The print shop charges [tex]$1.10 per square foot for the banner. So, the cost \(C\) can be calculated as: \[ C = \text{Area} \times \text{cost per square foot} \] \[ C = 26.83 \times 1.10 \] \[ C \approx 29.52 \] ### Step 5: Compare the calculated cost with the provided options The calculated cost of the banner is approximately $[/tex]29.52 before tax. The provided options for the banner are:

- [tex]$41.95 - $[/tex]46.14
- [tex]$83.90 - $[/tex]92.30

None of the provided options match the calculated cost.

Therefore, verifying the calculations provides the conclusion that the cost for the banner before tax is:
[tex]\[ \$ 29.52 \][/tex]

Hence, the closest approximation should be considered as the direct result.