# solving a triangle >.<

• February 7th 2010, 12:12 AM
sherwin156
solving a triangle >.<
1.A regular pentagon is inscribed in a circle whose radius 18cm. Find the perimeter of the pentagon.

2.Find the radius of the circle circumscribed about the triangle for which A=50deg. B=15deg a=70cm
• February 7th 2010, 02:12 AM
Solarmew
$
\frac{360}{5} = 72^{\circ} \therefore \angle O = 72^{\circ}
$

find the missing side using the law of cosine and you'll find the perimeter