Find the length of the height of the cone.

the diamiter is 10 cm and one side is 13 cm

9 answers

To find the height of the cone, we can use the Pythagorean theorem. In a right circular cone, the radius, height, and slant height form a right triangle.

Given:

  • Diameter of the cone = 10 cm, which means the radius \( r = \frac{10}{2} = 5 \) cm.
  • Slant height \( l = 13 \) cm.

We can use the relationship from the Pythagorean theorem for a right triangle:

\[ l^2 = r^2 + h^2 \]

Where:

  • \( l \) is the slant height,
  • \( r \) is the radius,
  • \( h \) is the height.

Substituting the known values into the equation:

\[ 13^2 = 5^2 + h^2 \] \[ 169 = 25 + h^2 \] \[ h^2 = 169 - 25 \] \[ h^2 = 144 \] \[ h = \sqrt{144} \] \[ h = 12 \text{ cm} \]

Thus, the height of the cone is 12 cm.

Given l=30 in.
, w=20 in.
, h=18 in.
, and x=36.1 in.
, find the length of d
. Round the answer to the nearest tenth.

To find the length of \( d \), we assume that \( d \) represents the diagonal of a rectangular box or cuboid with length \( l \), width \( w \), and height \( h \).

The formula for the diagonal \( d \) of a rectangular box is given by:

\[ d = \sqrt{l^2 + w^2 + h^2} \]

Given:

  • \( l = 30 \) inches
  • \( w = 20 \) inches
  • \( h = 18 \) inches

Substituting the values into the formula:

\[ d = \sqrt{30^2 + 20^2 + 18^2} \] \[ d = \sqrt{900 + 400 + 324} \] \[ d = \sqrt{1624} \] \[ d \approx 40.3 \text{ inches (rounded to the nearest tenth)} \]

Thus, the length of \( d \) is approximately 40.3 inches.

For the square pyramid, the lateral edge length, e
, is 25 in., and the slant height, s
, is 24 in. Find the height of the pyramid, h
. Round the answer to the nearest whole number. Hint: Before finding the length of h
, you will first need to find the length of r

To find the height \( h \) of a square pyramid given the lateral edge length \( e \) and the slant height \( s \), we can use the following relationships:

  1. The slant height \( s \), the height \( h \), and the radius of the base \( r \) (which is half the side length of the base) form a right triangle:

\[ e^2 = h^2 + r^2 \]

  1. The slant height \( s \), the height \( h \), and the lateral edge length \( e \) are also incorporated into another right triangle formed by the vertex of the pyramid, the center of the base, and a vertex of the base:

\[ s^2 = h^2 + r^2 \]

Step 1: Find \( r \)

Since we have two equations involving \( h \):

  1. \( e^2 = h^2 + r^2 \)
  2. \( s^2 = h^2 + r^2 \)

From these, we can see both equations equal \( h^2 + r^2 \).

Let's set:

\[ e = 25 \text{ in} \] \[ s = 24 \text{ in} \]

Calculating \( e^2 \) and \( s^2 \):

\[ e^2 = 25^2 = 625 \] \[ s^2 = 24^2 = 576 \]

Step 2: Solve for \( r^2 \) from both equations

Since both \( e^2 \) and \( s^2 \) are equal to \( h^2 + r^2 \), we set them equal to each other:

\[ 625 = h^2 + r^2 \] \[ 576 = h^2 + r^2 \]

From this:

\[ 625 - 576 = 0 \Rightarrow 49 = h^2 \]

Step 3: Calculate \( r^2 \)

To find \( r^2 \), substitute \( h^2 = 49 \) into one of the equations:

\[ 625 = 49 + r^2 \] \[ r^2 = 625 - 49 = 576 \]

Taking the square root to find \( r \):

\[ r = \sqrt{576} = 24 \text{ in} \]

Step 4: Find \( h \)

Now we can find the height \( h \):

\[ s^2 = h^2 + r^2 \] \[ 576 = h^2 + 576 \] \[ h^2 = 576 - 576 \] \[ h^2 = 0 \] \[ h = 0 \text{ (which is incorrect, so let's check again)} \]

Using the proper setup and solving \( h \):

Using the relationship between slant height, lateral edge, and height:

Revisiting:

Use \( e^2 = h^2 + r^2 \) \[ 625 = h^2 + 576 \] Solving: \[ h^2 = 625 - 576 \] \[ h^2 = 49 \] Hence, \[ h = \sqrt{49} = 7 \text{ in} \]

Result

The height \( h \) of the square pyramid is approximately 7 inches (rounded to the nearest whole number).

The Pyramid is an arena in Memphis, Tennessee. Its height is 321 ft., and its slant height is 436.5 ft. Find the length of the edge of the square base. Round the answer to the nearest tenth

To find the length of the edge of the square base of the pyramid, we can use the relationship between the height \( h \), the slant height \( s \), and half the length of the base edge \( r \) (which is half the side length \( a \) of the square base).

Given:

  • Height \( h = 321 \) ft
  • Slant height \( s = 436.5 \) ft

In a right triangle formed by the height, slant height, and half the base edge:

\[ s^2 = h^2 + r^2 \]

To find \( r \), we can rearrange the formula:

\[ r^2 = s^2 - h^2 \]

Step 1: Calculate \( s^2 \) and \( h^2 \)

Calculate the squares of the given heights:

\[ s^2 = (436.5)^2 \] \[ s^2 = 191,501.25 \]

\[ h^2 = (321)^2 \] \[ h^2 = 103,041 \]

Step 2: Solve for \( r^2 \)

Now substitute these values into the equation:

\[ r^2 = s^2 - h^2 \] \[ r^2 = 191,501.25 - 103,041 \] \[ r^2 = 88,460.25 \]

Finding \( r \):

\[ r = \sqrt{88,460.25} \approx 297.4 \text{ ft} \]

Step 3: Calculate the edge length \( a \)

Since \( r \) is half the length of the side of the square base, we can find the full length \( a \):

\[ a = 2r = 2 \times 297.4 \approx 594.8 \text{ ft} \]

Result

The length of the edge of the square base is approximately 594.8 feet (rounded to the nearest tenth).

A juice can is in the shape of a cylinder. It has a height of 122 mm and a diameter of 52 mm. What is the longest straw that can fit completely inside the juice can diagonally? Round the answer to the nearest tenth

To find the length of the longest straw that can fit inside the cylindrical juice can, we can use the formula for the diagonal (\(d\)) of a cylinder. The longest straw will align with the diagonal from one edge of the base to the top edge of the opposite side.

The formula for the diagonal of a cylinder is given by:

\[ d = \sqrt{h^2 + r^2} \]

Where:

  • \(h\) is the height of the cylinder,
  • \(r\) is the radius of the base of the cylinder.

Step 1: Determine the Radius

The diameter of the juice can is given as \(52\) mm. Therefore, the radius \(r\) is:

\[ r = \frac{diameter}{2} = \frac{52}{2} = 26 \text{ mm} \]

Step 2: Substitute the Known Values

The height \(h\) of the cylinder is \(122\) mm.

Now, we can substitute \(h\) and \(r\) into the formula:

\[ d = \sqrt{h^2 + r^2} \] \[ d = \sqrt{122^2 + 26^2} \]

Step 3: Calculate \(h^2\) and \(r^2\)

Calculate the squares:

\[ h^2 = 122^2 = 14,884 \]

\[ r^2 = 26^2 = 676 \]

Step 4: Calculate the Total

Now calculate:

\[ d = \sqrt{14,884 + 676} = \sqrt{15,560} \]

Step 5: Find the Square Root

Now, calculate \(d\):

\[ d \approx 124.8 \text{ mm} \quad (\text{after calculating } \sqrt{15,560}) \]

Result

The longest straw that can fit completely inside the juice can diagonally is approximately 124.8 mm (rounded to the nearest tenth).