Answer:
42 square inches
Step-by-step explanation:
Area of a triangle = (1/2)(base)(height)
A = 1/2(12)(7)
A = 1/2(84)
A = 42
let X = speed of slow bicycle rider
2x=speed of fast bicycle rider
3(x+2x)=72
X=8mph(slowest bicycle rider)
2x=16mph(fastest bicycle rider)
16
1, 2, 3, 4, 6, 7, 8, 12, 14, 21, 24, 28, 42, 56, 84, 168