Question

[Đinh Thúy Hiền]

cho tam giac ABC co AB + AC = 25 cm , AC + BC = 35cm , BC + AB = 30 cm 

a, Tinh chu vi ta giac ABC 

b tinh so do moi canh tam giac do

Answer 1

[Oxford Đinh]

AB + AC = 25 cm

AC + BC = 35 cm

 BC + AB = 30 cm

\(\Rightarrow\)AB + AC + AC + BC + BC + AB = 25 + 35 + 30 =90 cm

2 (AB + BC + AC) = 90 cm

AB + BC + AC = 90 : 2 =45 cm

AB + AC = 25 cm

\(\Rightarrow\)BC = 45 - 25 = 20 cm

AC + BC = 35 cm

\(\Rightarrow\)AB = 45 -35 = 10 cm

BC + AB = 30cm

\(\Rightarrow\)AC = 4 5 - 30 = 15 cm