mohon jwb bsk dikumpulin

1. =1/2×d1×d2
=1/2×21×16
=1/2×336
=336/2=168cm2

2. =2×L/d1+d1
=2×250/10+10
=500/20=25cm

3. =2×L/(a+b)
=2×3060/(70+100)
=6120/170
=36cm

4. =22/7×21×21
=1386m2

5. =28×L/22
=43,12/22
=1,96
=akar pangkatin 2(1,96nya)
=r=1,4
=d=1,4×2=2,8
=d=2,8dm