Tolong dibantu beserta caranya yha.. Plizzz

luasnya = 30cm²
semoga membantu

A+B+C = kll segitiga
3x + x+1 + 3x+1 = 30
3x + x + 3x + 1 + 1 = 30
7x +2 =30
7x = 30-2
7x = 28
x = 28/7
x = 4

alas = x+1 = 4+1=5
tinggi = 3x = 3.4 =12