Quiz :-:

Jawaban:

B

Penjelasan dengan langkah-langkah:

Luas trapesium = jumlah sejajar x tinggi ÷ 2

180 = 2x(x + 4 + 3x + 2)/2

180/2 = x(4x + 6)/2

x(2x + 3) = 90

2x² + 3x – 90 = 0

(2x + 15)(x – 6) = 0

x = 6

x + 4 = 10

3x + 2 = 20

2x = 12

s = √(12² + {[20–10]/2}²)

s = √(144 + 25)

s = √169

s = 13 cm

Keliling = 10 + 20 + 2(13)

= 30 + 26

= 56 cm

d o n e .....

javier

Menentukan nilai x.

L = jumlah sisi jejajar × tinggi /2

180 = ( (x + 4) + (3x + 2) ) × 2x /2

180 × 2 = (x + 4 + 3x + 2) × 2x

360 = (4x + 6) × 2x

360 = 8x² + 12x

8x² + 12x – 360 = 0

2x² + 3x – 90 = 0

(2x + 15)(x – 6) = 0

x = -15/2 = -7,5

x = 6 —-> ambil nilai positif.

Menentukan panjang sisi trapesium:

• (x + 4) m = (6 + 4) m = 10 m
• (3x + 2) m = (3(6) + 2) m = 20 m.

tinggi: 2x m = 2(6) m = 13 m

…

Menentukan sisi miring:

s² = 12² + (20-10-5)²

s² = 144 + 5²

s² = 144 + 25

s² = 169

s = √169

s = 13 m

…

Menentukan keliling:

K = jumlah sisi sejajara + 2(sisi miring)

K = (10 + 20) + 2(13)

K = 30 + 26

K = 56 m

opsi B