giúp em với

N

nguyenbahiep1

2 tam giác này bằng nhau ta có thể coi

góc A = góc D
góc B = góc E
góc C = góc F

[TEX]\hat{A} = \frac{1}{2}\hat{E} = \frac{1}{2}\hat{B} \\ \hat{B} = \frac{1}{3}\hat{F} = \frac{1}{3}\hat{C} \Rightarrow \hat{C} = 3.\hat{B} \\ \hat{A} + \hat{B} + \hat{C} = 180^o \Leftrightarrow \frac{1}{2}\hat{B}+\hat{B}+3.\hat{B} = 180^o \Rightarrow \frac{9}{2}\hat{B} = 180^o \\ \Rightarrow \hat{B} = 40^o \\ \hat{A} = 20^o \\ \hat{C} = 120^o[/TEX]
 
You must log in or register to reply here.
Top Bottom