Expert: Abe Mantell - 9/11/2005

Question
1. simple interest
solve for r:I=Prt
2.height of an equilateral triangle
solve for s:h=V3S/2
3.volume of a right circular cone
solve for h:V=pr2h/3 the p is for the pi symbol
4.area of a trapezoid
solve for b1:A=h/2(b1+b2)
5.lateral surface area of a frustrum of a right circular cone solve for R:S=ps(R+r)please help thank you  

Answer
Hello Mariana,

1. Divide by P and t, to get: r=I/(Pt)

2. (I'll use sqrt(3) for the "square root of 3")
-- h=sqrt(3)s/2...multiply by 2/sqrt(3) to get:
-- s=2h/sqrt(3)

3. (I'll use r^2 for "r squared")
-- multiply by 3/(Pi*r^2), to get: h=3V/(Pi*r^2)

4. multiply by 2/h to get: b1+b2=2A/h, now
-- subtract b2 to get: b1=2A/h-b2

5. S=Pi*s(R+r), divide by Pi and , to get:
-- R+r=S/(Pi*s), now subtract r: R=S/(Pi*s)-r

Abe