tolong jawab dong lagi buru2 makasih

Kell segitiga = s+s+s
140 = 3x+(3x+2)+(2x-2)
140 = 3x+3x+2+2x-2
140 = 3x+3x+2x+2-2
140 = 8x
x = 140:8
x = 17.5 cm

L segitiga = ½×a×t
L segitiga = ½×(2x-2)×(3x)
L segitiga = ½×(2(17.5)-2)×(3(17.5))
L segitiga = ½×33×52.5
L segitiga = ½×1732.5
L segitiga = 866.25