Помогите решить задачи по геометрии пожалуйста

АB = 12
AC = 6v3
AS = 6v3
CS = 6v6

S1 = S(ABC)= 1/2 * 6 * 6v3 = 18v3
S2 = S (ACS) = 1/2 * 6v2 * 6v2 = 36
S3 = S ( ABS) = 1/2 * 12 * 6v3 =36v3
S4 = S (CBS) = 1/2 * 6 * 6v6 = 18v6