Kak Tanya nomor 4 Gimana?

luas ΔDGF
L = ½ x DG x GF
= ½ x ( 14 + 5 ) x ( 12 )
= ½ x 19 x 12
= 19 x 6
= 114 cm²

luas ΔEGF
L = ½ x EG x GF
= ½ x 5 x 6
= 5 x 3
= 15 cm²


luas ΔDEF
L = L ΔDGF - L ΔEGF
= 114 cm² - 15 cm²
= 99 cm²