Help needed! Trying to get answer

Liula [17]

Answer:

volume = 140 cubic units

area = 183.3 square units

Step-by-step explanation:

I am going to assume we are dealing with a pyramid with a rectangular base. The rectangular base has length 7 units, width 5 units, and height 12 units.

Let's do the volume first since it's simpler.

Volume:

volume of pyramid = (1/3) * (area of base) * height

volume = (1/3) * 7 units * 5 units * 12 units

volume = 140 cubic units

Now we deal with the surface area.

The total surface area of a rectangular pyramid is the sum of the lateral area and the area of the base. The area of the base is the area of a rectangle. The lateral area is the sum of the areas of the 4 triangular sides. Each two opposite sides are congruent. For the base, we have the length and width of the rectangular base, so we can find the area easily.

For the 4 triangular sides, we need to find the the height of the triangles. Since each pair of opposite faces is congruent, we have two triangles we need to find the heights for. I'll call the heights "p" and "q". We use the Pythagorean theorem to find the heights of the triangular faces.

a^2 + b^2 = c^2

(3.5)^2 + (12)^2 = p^2

p^2 = 156.25

p = 12.5

(2.5)^2 + (12)^2 = q^2

q^2 = 150.25

q = 12.25765

Area of triangle = (1/2) * base * height

For two of the triangles, the base is 5 and the height is 12.5.

For the other two of the triangles, the base is 7 and the height is 12.25765.

total surface area = area of base + 2(area of triangle with base 5) + 2(area of triangle with base 7)

A = LW + 2(1/2)(base)(height) + 2(1/2)(base)(height)

A = 7(5) + 2(1/2)(5)(12.5) + 2(1/2)(7)(12.25765)

A = 183.3 square units

8 0

3 years ago

Read 2 more answers

Solve the following equation: r2+6r=27

Feliz [49]

2r+6r=27

8r=27
*divide both side by 8
r=3.75

3 0

4 years ago

Read 2 more answers

Which of these graphs represents a function?

Vlad1618 [11]

The answer is X.
In order for it to be a function, there should be only one y-value for every x-value. Graph x is the only one that obeys this rule, therefore it is the answer

7 0

3 years ago

Mrs. Wing is preparing to tape up posters made by her students on the wall. She cuts tape into 1/4 foot pieces. How many 1/4 foo

Step2247 [10]

Answer:

20 pieces of tape.

Step-by-step explanation:

Okay, so first you have to realize that 1/4 of a foot means there is 4 pieces in a foot. So at this point you need to say there is 5 groups of four because 4 pieces of tape in a foot. So 5 times 4 is 20 pieces of tape.

8 0

3 years ago

The bar graph shows the numbers of reserved campsites at a campground for one week. What percent of the reservations were for Fr

Slav-nsk [51]

Answer:

66.67 %

Step-by-step explanation:

As we can see from the figure

We are given a bar graph in which bars represent the number of reserved campsites at a camp ground for one week from Monday to Sunday.

First of all

Lets the count the total number of reservations made by campsites during the week.

Total Number of campsite reservations = 5+3+4+7+26+30+9