21-25. ............tolonggg

21. 90-74=16°
22. gua gk tau
23. L=π×r²
=22/7×14×14
=22×2×14=616
Ljuring=45/360×616
=1/8×616=77cm²
24. sudut=s
s ACB=90-s BCD
=90-50=40°
s ADB=s ACB=40°
s ADC=90-s ADB
=90-40=50°
s BXC=180-(s ADC+s BCD)
=180-(50+50)
=180-100=80°
s AXD=180-s DXC=180-80
=100°
s CBD=180-(s BXC+s ACB)
=180-(100+40)
=180-140=40°
25.