= 24 units
Therefore; using the Pythagoras theorem;
S² = (S/2)² + h²; where h is the height of the equilateral triangle
S² =S²/4 + (4√3)²
S² = S²/4 + 48 ; Multiplying everywhere by 4; we get
4 S² = S² + (48×4)
3 S² = 192
S² = 64
S = 8
but, perimeter of an equilateral triangle is side × 3
Perimeter= 8 × 3
= 24 units