Question

Tolong jawab dongg aku kurang paham kalo yang begini

Answer 1

1.
A : B : C = 2 : 3 : 4
jumlah seluruh sudut segitiga harus 180
a.
sudut a = x 180 = 40
sudut b = x 180 = 60
sudut c = x 180 = 80
b.
sudut terbesar = 80, sudut terkecil = 40

2.
alas : tinggi = 7a : 4a
luas = 1/2. alas. tinggi
126 = 1/2. 7a . 4a
126 = 14
= 126/14
a = = 3
maka alas = 7a = 7 x 3 = 21

c.
K= jumlah panjang sisi
280 = (3x+20) + (5x - 16) + (6x -4)
280 = 14x
x =  20

alas = 5x - 16 =5(20) - 16 = 84
tinggi = 3x + 20 = 3(20) + 20 = 80
sisi miring = 6x - 4 = 6(20) - 4 = 116

luas = 1/2 x alas x tinggi = 1/2 x 84 x 80 = 3360