Resposta :
Explicação passo a passo:
a) A = (b.h)/2
A = (12.2/3) / 2
A = (24/3) / 2
A = 8/2
A = 4cm²
b) A = (b.h)/2
A = (10,5 . 4,5) / 2
A = 47,25 / 2
A = 23,625 cm²
c) A = (b.h)/2
A = (3/5 .20) / 2
A = (60/5) / 2
A = 12 / 2
A = 6 cm²
d) A = (b.h)/2
A = (18,2.14,5) / 2
A = 263,90 / 2
A = 131,95 cm²
e) A = (b.h)/2
A = (24 . 9) / 2
A = 216/2
A = 108 cm²