jari jari lingkaran luar dimana sisi sisi segitiga a=9cm,b=6cm,dan c=5cm adalah. bantu yah dikumpulkan besok

s = 1/2 x keliling
s = 1/2 x (9 + 6 + 5)
s = 1/2 x 20
s = 10 cm

r = abc / 4L
r = abc / 4 √s (s - a) (s - b) (s - c)
r = (9 x 6 x 5) / 4 √10 (10 - 9) (10 - 6) (10 - 5)
r = 270 / 4 √ 10 x 1 x 4 x 5
r = 270 / (4 √200)
r = 270 / (40 √2)
r = 270/80  √2
r = 27/8 √2 cm

s = ¹/₂ . keliling Δ
   = ¹/₂ . (9 cm + 6 cm + 5 cm)
   = ¹/₂ . 20 cm
   = 10 cm

LΔ = √(s(s-a)(s-b)(s-c))
     = √(10 cm(10 cm - 9 cm)(10 cm - 6 cm)(10 cm - 5 cm)
     = √10 cm(1 cm)(4 cm)(5 cm)
     = √200 cm
     = 10√2 cm²

r = abc / 4L
  = 9 cm . 6 cm . 5 cm / 4(10√2 cm²)
  = 240 cm / 20√2 cm²
  = 28,284 cm