geometry help!?!?

[stephenie-jayne]

Hi i was wondering if someone would be able to help me out with a few things with my maths. its not my strongest subject. i have trouble with total surface area, i know how to work it out for pyramids, prisms and spheres ect, however i dont know how to calculate the unknown dimentions of them i only know how to calculate the unkown dimentions for a cube
eg x divided by 6 and then square root it.
Would someone please help me with the formulas to work out for a
-cubid
-cylinder
-cone
-and sphere?

Also i have the same problem working out the unknown dimentions for the volume of prisms, pyramids and spheres with the same shapes!

pleassssseeeeee help!!!!!??!!!

[WattZ]

so your just wanting the formula's? not sure if I read it right but let me know specifically if you need examples, etc. All of these have simple examples on them in Maths Quest 12 further Maths textbook if you have it.

Areas
Acuboid = 2(lw +lh + wh)
Acyclinder = 2*pi*r*(r +h)
Acone = pi*r*(r + slant height)
Asphere = 4*pi*r²

(Shown in exercise 7C)

Volumes:

Vsphere = 4/3*pi*r³
Vpryamid = 1/3*area of base*h
Vprism = Area of cross section*h

(shown in Exercise 7D)

and if you didn't know:
R is radius, H is height, L is length, W is width