Tolong aku dong 1 sampai 3(ㆁωㆁ)

Tolong aku dong 1 sampai 3(ㆁωㆁ)

No 1 ( A )

$k = 20 + 29 + 21 \ = 70 : m \ l = frac{1}{2} a.t \ = frac{1}{2} .21.20 \ = frac{1}{2} .420 \ = 210 : m {}^{2}$

$k = 19 + 18 + 20 \ = 57cm \ l = frac{1}{2} .a.t \ = frac{1}{2} .20.16 \ = frac{1}{2} .320 \ = 160 : cm {}^{2}$