document.write( "Question 1210363: A cone has a radius of 10cm and slant height of 26cm. find the volume of the cone \n" ); document.write( "
Algebra.Com's Answer #852075 by CPhill(1959)![]() ![]() You can put this solution on YOUR website! Here's how to find the volume of the cone:\r \n" ); document.write( "\n" ); document.write( "**1. Understand the Formulas**\r \n" ); document.write( "\n" ); document.write( "To find the volume of a cone, you need its radius ($r$) and its height ($h$). The formula for the volume of a cone is:\r \n" ); document.write( "\n" ); document.write( "$V = \frac{1}{3} \pi r^2 h$\r \n" ); document.write( "\n" ); document.write( "You are given the radius ($r = 15 \text{ cm}$) and the slant height ($l = 20 \text{ cm}$), but you need to find the height ($h$).\r \n" ); document.write( "\n" ); document.write( "**2. Find the Height (h)**\r \n" ); document.write( "\n" ); document.write( "The radius, height, and slant height of a cone form a right-angled triangle, with the slant height as the hypotenuse. We can use the Pythagorean theorem:\r \n" ); document.write( "\n" ); document.write( "$r^2 + h^2 = l^2$\r \n" ); document.write( "\n" ); document.write( "Substitute the given values: \n" ); document.write( "$15^2 + h^2 = 20^2$ \n" ); document.write( "$225 + h^2 = 400$ \n" ); document.write( "$h^2 = 400 - 225$ \n" ); document.write( "$h^2 = 175$ \n" ); document.write( "$h = \sqrt{175}$\r \n" ); document.write( "\n" ); document.write( "To simplify $\sqrt{175}$: \n" ); document.write( "$175 = 25 \times 7$ \n" ); document.write( "$h = \sqrt{25 \times 7} = 5\sqrt{7} \text{ cm}$\r \n" ); document.write( "\n" ); document.write( "**3. Calculate the Volume (V)**\r \n" ); document.write( "\n" ); document.write( "Now that you have the height, plug the values of $r$ and $h$ into the volume formula:\r \n" ); document.write( "\n" ); document.write( "$V = \frac{1}{3} \pi r^2 h$ \n" ); document.write( "$V = \frac{1}{3} \pi (15)^2 (5\sqrt{7})$ \n" ); document.write( "$V = \frac{1}{3} \pi (225) (5\sqrt{7})$ \n" ); document.write( "$V = 75 \pi (5\sqrt{7})$ \n" ); document.write( "$V = 375\sqrt{7}\pi \text{ cm}^3$\r \n" ); document.write( "\n" ); document.write( "**4. Approximate the Value (Optional)**\r \n" ); document.write( "\n" ); document.write( "If you need a numerical approximation, use $\pi \approx 3.14159$ and $\sqrt{7} \approx 2.64575$:\r \n" ); document.write( "\n" ); document.write( "$V \approx 375 \times 2.64575 \times 3.14159$ \n" ); document.write( "$V \approx 992.15625 \times 3.14159$ \n" ); document.write( "$V \approx 3117.85 \text{ cm}^3$\r \n" ); document.write( "\n" ); document.write( "The exact volume of the cone is $375\sqrt{7}\pi \text{ cm}^3$. \n" ); document.write( "Approximately, the volume is $3117.85 \text{ cm}^3$. \n" ); document.write( " |