Answer:
expression for perimeter 3x+12
expresion for area ( 2x+6) ( x+4) /2
P= 29; A = 72
Explanation:
Given : hight 2x+6, base length x+4 and triangle is equilateral
perimeter = base + two other sides
because the triangle is equilateral the base length is the same as the other two sides
perimeter = x+4 + x+4 +x+4 = 3x + 12
area = base *hight / 2 = (x+4) ( 2x+6) /2
if x=5
P = 3*5 +12 = 29, A = (5+4) ( 2*5+6)/2 = 9* 16/2 = 144/2 = 72