Answer:
B
Step-by-step explanation:
ABCD is a trapezium with area (A) calculated as
A = [tex]\frac{1}{2}[/tex] AD(AB + CD)
Calculate AD using right triangle ABD
Area of ΔABD = 0.5 × AD × AB = 280, that is
0.5 × AD × 16 = 280
8AD = 280 ( divide both sides by 8 )
AD = 35
Thus the area of trapezium ABCD is
A = [tex]\frac{1}{2}[/tex] × 35(16 + 20)
= [tex]\frac{1}{2}[/tex] × 35 × 36 = 18 × 35 = 630 → B
