What is he doing?

He is flying the kite

How old is he?

He is nineteen years old

What is his hobby ?

Where is he from?

His hobby is reading book

He is from England

leaves / returns

doesn't like

is staying / lives 

wears/ works / is wearing

The red car is more expensive than the black car

That film is more boring than  this one

Your kitchen is bigger than my kitchen

a, Do MN ⊥ Ax , MN ⊥ Cy => Ax // Cy ( từ vuông góc đến song song)

b, Kẻ Bz // AB // Cy

Do Ax // Bz \(\Rightarrow\widehat{A}=\widehat{B_1}=40^o\)(2 góc so le trong)

Do Bz // Cy \(\Rightarrow\widehat{B_2}=\widehat{C}=50^o\)

Ta thấy: \(\widehat{ABC}=\widehat{B_1}+\widehat{B_2}=40^o+50^o=90^ohayAB\perp BC\left(dpcm\right)\)

a, Giả sử: Cz // Ax // By

Do Cz // Ax \(\Rightarrow\widehat{A}+\widehat{C_1}=180^o\)(2 góc TCP)

                   \(\Rightarrow80^o+\widehat{C_1}=180^o\)

                    \(\Rightarrow\widehat{C_1}=180^o-80^o=100^o\)

Do Cz // By \(\Rightarrow\widehat{C_2}=\widehat{B}=35^o\)(2 góc so le trong)

Ta thấy: \(\widehat{ACB}=\widehat{C_1}+\widehat{C_2}=100^o+35^o=135^o\)

b, Do d // AC \(\Rightarrow\widehat{ACB}+\widehat{EBC}=180^o\)(2 góc TCP)

                      \(\Rightarrow135^o+\widehat{EBC}=180^o\)

                       \(\Rightarrow\widehat{EBC}=180^o-135^o=45^o\)                       

B. 721 x 5 = 3605

D