pada gambar disamping, besar sudut A adalah... a.10° b.40° c.60° d.70°

4x + 6x + 80 = 180*
10x = 180* - 80*
10x = 100*
x = 100* ÷ 10*
x = 10*

<A = 4x = 4(10*) = 40*

jawaban b