different area triangle from n points code example

Example 1: how to find vertices of triangle if area is given

(1/2)*abs( x1 * (y2 - y3) + x2 * (y3 - y1) + x3 * (y1-y2) ) , where (x1, y1) , (x2, y2) and (x3, y3) are the vertices of the triangle

Example 2: how to find the area of a triangle

#this is the code to find the area of a parrelogram and triangle
#change the numbers to select what height and base your shape is

b = 3 #b is base 
h = 3 #h is height (middle)


t = 5 #this is the base of the triangle
i = 5 #and this is the height
p = t*i #dont touch this


print("this is the area of the parrelogram")
print(b * h)

m = input("do you want to calculate a triangle? (space before answer)") 

print(m)

if m == " yes":
    print ("this is the area of the triangle that you inputed")
    print (p/2)
else:
    print("ok")