Besar sudut ABC adalah…..A.20⁰B.40⁰C.120⁰D.140⁰tolong dijawab dengan caranya​

★ SUDUT ★

Cari nilai x

<A + <D = 180°

2x + 7x = 180°

9x = 180°

x = 180°/9

x = 20°

Cari nilai y

<B + <C = 180°

x + 2y + 6y = 180°

20° + 8y = 180°

8y = 180° – 20°

8y = 160°

y = 160°/8

y = 20°

Besar sudut A

= 2x

= 2(20)°

= 40°

Besar sudut B

= x + 2y

= 20° + 2(20)°

= 20° + 40°

= 60°

Besar sudut C

= 6y

= 6(20°)

= 120°

Besar sudut D

= 7x

= 7(20)°

= 140°

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