The equation for the value of 'a" is 2A/p
The subject of formula is a way of representing a variable as a function of another.
Given the expression
A = 1/2 ap
We are to make a the subject of the formula
A = ap/2
Cross multiply
2A = ap
Divide both sides by p
2A/p = a
a = 2A/p
Hence the equation for the value of 'a" is 2A/p
Learn more on subject of formula here: https://brainly.com/question/657646
#SPJ1