Code

//area triangle

function areati()  {

var base = prompt ("Base")

var height = prompt ("Height")

var sum = (1/2)*base*height

alert("Area : "+sum+"")

}

//area circle

function areac()  {

var radius = prompt ("Radius")

var pi = "3.14159"

var sum = radius*radius*pi

alert("Area "+sum+"")
}

//area rectangle

function arear()  {

var length = prompt ("Length")

var width = prompt ("Width")

var sum = width*length

alert("Area "+sum+"")
}

//area trapezoid

function areata()  {

var baseone = prompt ("Base one")

var basetwo = prompt ("Base two")

var height = prompt ("Height")

var sum = (1/2)*height*(baseone+basetwo)

alert("Area "+sum+"")
}

//area rhombus

function arearh()  {

var onediag = prompt ("1st diagonal")

var twodiag = prompt ("enter the 2nd diagonal")

var sum = onediag*twodiag*(1/2)

alert("the area is "+sum+"")
}

//area oval

function areao()  {

var length = prompt ("enter the length")

var height = prompt ("enter the height")

var pi = 3.14159

var sum = (pi*length)/height

alert("the area is "+sum+"")
}

//volume rect prism

function volumerp()  {

var length = prompt ("enter length")

var width = prompt ("enter width")

var height = prompt ("enter height")

var sum = length*width*height

alert("the volume is "+sum+"")
}