\(\Delta\)ABC = \(\Delta\)MNP

=> \(\hept{\begin{cases}\widehat{A}=\widehat{M}=45^o\\\widehat{B}=\widehat{N}=70^{^o}\\\widehat{C}=\widehat{P}\end{cases}}\)

=> \(\widehat{C}=\widehat{P}=180^o-\left(45^o+70^o\right)=65^o\)

a: \(\widehat{B}=\widehat{C}=45^0\)

b: \(\widehat{P}=180^0-2\cdot45^0=90^0\)

Cho tam giác ABC= tam giác MNP biết A=450 ; P=600. Khi đó B= 30⁰

đoán thui

Ta có tam giác ABC = tam giác MNP 

=> AB = MN = 5 cm 

=> AC = MP = 8 cm 

Lại có : \(P_{MNP}=MN+NP+MP=20\)

\(\Rightarrow5+8+NP=20\Leftrightarrow NP=7\)cm 

Vậy AB = 5 cm ; NP = 7 cm ; MP = 8 cm 

Ta có: \(\left\{{}\begin{matrix}\widehat{A}=\widehat{M}=80^0\\\widehat{B}=\widehat{N}=180^0-\widehat{A}-\widehat{C}\\\widehat{C}=\widehat{P}=45^0\end{matrix}\right.\)\(\left(\Delta ABC=\Delta MNP\right)\)

\(\Rightarrow\left\{{}\begin{matrix}\widehat{A}=\widehat{M}=80^0\\\widehat{B}=\widehat{N}=180^0-80^0-45^0=55^0\\\widehat{C}=\widehat{P}=45^0\end{matrix}\right.\)

Ta có : MN + NP +MP = 25

MN + 7 + MP = 25

MN + MP = 25 - 7 = 18

Ta có : MN + MP = AB + AC = 18 cm

( vì tam giác ABC = tam giác MNP )

Mà AB-AC = MN-MP = 2 cm

( Vì tam giác ABC = tam giác MNP )

AB=MN= (18+2):2=10 (cm)

AC=MP=10-2=8 (cm)

Vậy AB = 10 cm

AC = 8 cm

BC=NP=7cm