Answer:

Step-by-step explanation:
The formula for the area of a triangle is 
The triangles that can be made is the triangle that has legs 20 and 50 and the triangle that has legs 20 and 10.
Since there are 2 of each triangles, we get:

The answer that fits is the first option.
-7 = 1 + 2/3n
Subtract 1 from both sides:
-8 = 2/3n
Multiply both sides by 3:
-24 = 2n
Divide both sides by 2:
N= -12
If necessary, convert all of these measurements to the same unit of measurement.
6 ft
15 yd = 45 ft
600 in= 50 ft
12 ft
640 in = 53 1/3 ft
Looks like no two of these measuremnts are equal. ;(