Jawabanmu

2014-03-18T21:04:20+07:00
D = 2r = 2 × luasΔ/s
d = 2 × 1/2 × 24 cm ×10 cm ÷ (24 cm + 10 cm + 26 cm)
d = 240 ÷ 60
d = 4 cm