The area of a trapezoid is 70.55 square feet. The lengths of the bases are 11.4 feet and 5.6 feet. What is the height of the trapezoid?

A. [tex]$4.15 \, \text{ft}$[/tex]
B. [tex]$4.15 \, \text{ft}^2$[/tex]
C. [tex]$8.3 \, \text{ft}$[/tex]
D. [tex]$8.3 \, \text{ft}^2$[/tex]



Answer :

To solve for the height of a trapezoid given the area and the lengths of the two bases, we can use the formula for the area of a trapezoid. The formula for the area [tex]\(A\)[/tex] of a trapezoid is given by:

[tex]\[ A = \frac{1}{2} \times (b_1 + b_2) \times h \][/tex]

where:
- [tex]\(A\)[/tex] is the area,
- [tex]\(b_1\)[/tex] is the length of the first base,
- [tex]\(b_2\)[/tex] is the length of the second base,
- [tex]\(h\)[/tex] is the height.

We are given:
- [tex]\(A = 70.55 \ \text{square feet}\)[/tex],
- [tex]\(b_1 = 11.4 \ \text{feet}\)[/tex],
- [tex]\(b_2 = 5.6 \ \text{feet}\)[/tex].

We need to find [tex]\(h\)[/tex], the height of the trapezoid. First, let's rearrange the area formula to solve for [tex]\(h\)[/tex]:

[tex]\[ A = \frac{1}{2} \times (b_1 + b_2) \times h \][/tex]

Multiply both sides by 2 to isolate the term with [tex]\(h\)[/tex]:

[tex]\[ 2A = (b_1 + b_2) \times h \][/tex]

Next, divide both sides by [tex]\((b_1 + b_2)\)[/tex]:

[tex]\[ h = \frac{2A}{b_1 + b_2} \][/tex]

Now, substitute the given values into the formula:

[tex]\[ h = \frac{2 \times 70.55}{11.4 + 5.6} \][/tex]

Calculate the denominator:

[tex]\[ 11.4 + 5.6 = 17 \ \text{feet} \][/tex]

Then, compute the height:

[tex]\[ h = \frac{2 \times 70.55}{17} = \frac{141.1}{17} \approx 8.3 \ \text{feet} \][/tex]

Therefore, the height of the trapezoid is approximately [tex]\(8.3\)[/tex] feet.

Of the given options:
- [tex]\(4.15 \ \text{ft}\)[/tex]
- [tex]\(4.15 \ \text{ft}^2\)[/tex]
- [tex]\(8.3 \ \text{ft}\)[/tex]
- [tex]\(8.3 \ \text{t}^2\)[/tex]

The correct choice is:
[tex]\[ \boxed{8.3 \ \text{ft}} \][/tex]