Question

Bantuin adek aku dong no. 3 & 4b

Answer 1

3. Lo= 3,14xr²
7850=3,14xr²
7850/3,14=r²
2500=r²
√2500=r
50=r

Ko = 2x3,14xr
=2x3,14x50
=100x3,14
=314 cm

4b.  Ljr BOC=<BOC/360xπr²
50=100/360xπr²
50x360/100=πr²
180=πr²
180/3,14=r²
57,3=r²
√57,3=r
7,5=r

Ljr AOB= 80/360x3,14x7,5²
=8/36x176,625
=1413/36
=39,25 cm²