Diketahui PQR besar pelurus R=130, besar P= (3×-10)°, Q= (3×+20)°. hitunglah

Sudut R = 180-130 = 50°
a. Besar x°
180 = 3x-10+3x+20+50
180 = 6x+60
180-60 = 6x
120 = 6x
20 = x
b. 50°
c. <Q = 3x +20 = 3. 20 + 20 = 80°
d. <P = 3x-10 = 3. 20 – 10 = 50°