Question

If a circle is inscribed in a triangle with sides of length x, y, and z, then the radius of the circle is given by the formula below.
r=√(s-x)(s-y)(s-z)) / s

Find the radius of a circle inscribed in a triangle that has sides of 2 cm, 4 cm, and 4 cm. Show your work.

Answer 1

Full question:
hi can u pls help me w/ a math problem?
If a circle is inscribed in a triangle with sides of length x, y, and z, then the radius of the circle is given by the formula below.
r=√(s-x)(s-y)(s-z)) / s where s= (x+y+z )/2

Find the radius of a circle inscribed in a triangle that has sides of 2 cm, 4 cm, and 4 cm. Show your work.

Answer 2

Is `/ s` in the square root?

Answer 3

yes it is

Answer 4

\[s=(2+4+4)/2=10/2=5 \\
\begin{align}
r&=\sqrt{\frac{(5-2)(5-4)(5-4)}{5} } \\
&=\sqrt{\frac{(3)(1)(1)}{5}} \\
&=\sqrt{\frac{3}{5} } \\
r&=\frac{\sqrt{15} }{5}~ \textrm{cm}
\end{align}\]

Answer 5

oh is that how u do it?

Answer 6

Yea, s is just half of the perimeter of the triangle. Once you know s, just plug and chug!

Answer 7

k thank u