yg d lingkari saja tolong bantuanya

40. rA = (√j²-l²) - rB
= (√13²-12²)-2
= (√169-144)-2
= (√25)-2
= 5-2
= 3 cm
LA : LB = 3² : 2² = 9 : 4

42. CBD = COD/2 = 44/2 = 22
ABD = 90-22 = 68°

43. AB = √(8+2)²-(8-2)² = √100-36 = √64 = 8 cm

44. panjang busur = 22/7 x 2 x 14 x 75/360
= 88 x 5/24
= 11x5/3
= 55/3
= 16⅔ cm

39. sudut BCD=50°

Sudut CAD = 180 ° - (sudut ADC+sudut BCD)

= 180° - (90 ° + 50 °) = 180 ° -140° = 40 °

sudut CBD = sudut CAD = 40°