Question

Vă rog mult!!!!!!!! Dau coroană ​

Answer 1

<A+<B+<C+<D=360°

$\tfrac{3B}{7}+B+\tfrac{3B}{7}+B=360\\2×\tfrac{3B}{7}+2B=360\\6B+14B=2520\\20B=2520\\B=126°\\ \\ \implies \boxed{\angle C= \tfrac{3B}{7}=\tfrac{378}{7}=54°}$

Answer 2

Fie <A=x si <B=y

$x = \frac{3}{7} y = \frac{3y}{7} \\ x + y = 180 \\ \frac{3y}{7} + y = 180 \\ \frac{3y + 7y}{7} = 180 \\ 10y = 1260 \\ y = 126 \\ x = 180 - 126 = 54$

<A=<C=54° d)