The figure below shows a solid cone if the total surface area of the cone is 1496 CM determine the slanting height of the cone if the diameter is 28m

1 answer

To find the slant height of the cone given the total surface area and the diameter, we can use the formula for the total surface area of a cone:

\[ \text{Total Surface Area} = \pi r (r + l) \]

where:

  • \( r \) is the radius of the base of the cone,
  • \( l \) is the slant height of the cone.

Step 1: Convert diameter to radius

Given the diameter of the cone is 28 m, we can find the radius:

\[ r = \frac{\text{diameter}}{2} = \frac{28}{2} = 14 \text{ m} \]

Step 2: Substitute the known values into the total surface area formula

The total surface area is given as 1496 cm². However, since we have calculated the radius in meters, we need to convert the surface area to square meters.

Since \( 1 \text{ cm}^2 = 0.0001 \text{ m}^2 \):

\[ 1496 \text{ cm}^2 = 1496 \times 0.0001 \text{ m}^2 = 0.1496 \text{ m}^2 \]

Now substitute \( r \) and the surface area into the formula:

\[ 0.1496 = \pi (14) (14 + l) \]

Step 3: Solve for \( l \)

First, calculate the area using the value of \( \pi \) (approximately 3.14):

\[ 0.1496 = 3.14 \cdot 14 \cdot (14 + l) \]

Calculate \( 3.14 \cdot 14 \):

\[ 3.14 \cdot 14 = 43.96 \]

Then, substitute this back:

\[ 0.1496 = 43.96 (14 + l) \]

Step 4: Isolate \( l \)

Now divide both sides by 43.96:

\[ \frac{0.1496}{43.96} = 14 + l \]

Calculating the left side:

\[ 0.0034 \approx 14 + l \]

Now isolate \( l \) by subtracting 14 from both sides:

\[ l = 0.0034 - 14 \]

This will yield:

\[ l \approx -13.9966 \]

This result appears unreasonable as the slant height cannot be negative. It's possible that there has been a misunderstanding regarding the measurement units or values provided. Please double-check the dimensions of the cone or any given values. Normally, if everything was accurate, the mathematics should yield a valid, positive slant height.

If there’s anything else or if the values need revision, let me know!