Jawaban:

penjumlahan sudut² dalam segitiga = 180°

1a. 65

b. 22,5

c. 24

d. 12,85

2a. 20

b. 80°

c. 20°

d. 80°

Penjelasan dengan langkah-langkah:

penjumlahan sudut² dalam segitiga = 180°

1a. 50°+2x°= 180°

2x° = 180°-50°= 130°

x = 65

b. 5x + 2x + x = 180°

8x = 180°

x = 180/8 = 22,5

c. 3x + 2x + 60 = 180°

5x +60 = 180

5x = 180-60

5x = 120

x = 120/5= 24

d. 3x + 4x + 90 = 180

7x + 90 = 180

7x = 180-90 = 90

x = 90/7= 12,85

2a. 4x + (2x+40) + x = 180

7x + 40 = 180

7x = 180-40 = 140

x = 140/7 = 20

b. sudut P = 2x + 40 = 2(20) +40 = 80°

c. sudut Q = x = 20°

d. sudut R = 4x = 4 (20) = 80°