Please minta bantuannya ya dari no 10-13 plus caranya ya:)

13 ) L hlm diluar kolam = L hlm - L kolam
= (10×8) - (4×6)
= 80 - 24
= 56 m^2 (B)
12) K = 2×( p+l )
36=2×(3x+4+2x+4)
5x + 8 = 36 / 2
5x = 18 - 8
x = 10 / 5
= 2 (A)
11) L segitiga ABC = 1/2 × a × t
= 1/2 × 12 × 12
= 72 cm^2 (B)
10) L segitiga ABC = 1/2 × a × t
= 1/2 × (10+8) × 8
= 1/2 × 18 × 8
= 72 cm^2 (A)
maaf bila ada penulisan angkanya yg salah sebab fotonya burem jadi kurang jelas