## adillie Group Title The base of a cone has a radius of 6 cm. The slant height of the cone is 15 cm. What is the height of the cone? one year ago one year ago

@jim_thompson5910

2. GoldPhenoix

You have to use the pythagorean theorem.

225=36+x so189 13.75?

4. jishan

l=|dw:1368934202007:dw|

5. GoldPhenoix

Or you can use the formula that jishan gave you.

is my answer right

7. jishan

yeah bro

8. jishan

h= height of cone r= radius & l=slant height

thank you

10. jishan

always welcome bros.

11. jim_thompson5910

Let r = radius s = slant height h = height $\large r^2 + h^2 = s^2$ $\large 6^2 + h^2 = 15^2$ $\large 36 + h^2 = 225$ $\large h^2 = 225-36$ $\large h^2 = 189$ $\large h = \sqrt{189}$ $\large h = \sqrt{9*21}$ $\large h = \sqrt{9}*\sqrt{21}$ $\large h = 3\sqrt{21}$ $\large h \approx 13.747727$ $\large h \approx 13.75$

12. geerky42

13. jim_thompson5910

you're very helpful and mature...