JAMB - Mathematics (2013 - No. 37)
If the angles of a quadrilateral are (3y + 10)°, (2y + 30)°, (y + 20)° and 4y°. Find the value of y.
66°
12°
30°
42°
คำอธิบาย
Sum of angles in a quadrilateral = 360°
\(\therefore\) (3y + 10) + (2y + 30) + (y + 20) + 4y = 360
10y + 60 = 360 \(\implies\) 10y = 300
y = 30°