By the operation of the problem
Take two points and use this formula x2 -x1/ y2 - y1.
Pick 100 km for D...
<span>This would yield T=100 minutes </span>
<span>Using the question stem we calculate 80 km were traveled in 1h (or 60 minutes).... </span>
<span>This leaves us with 40 minutes (2/3 of an hour) to travel 20km..... </span>
<span>R*T=D </span>
<span>R*2/3=20 </span>
<span>R=30 </span>
<span>Answer A....</span>
1) Given
2) m∠1 + m∠2 = 90°
3) BD bisects ∠ADC
4) definition of angle bisector
5) definition of congruency
6) m∠1 + m∠3 = 90°
7) ∠1 is complementary to ∠3 (7) definition of complementary
If there is a drop down box, and my answer is not an option, type in the options in the comment box and I will let you know which theorems (or definitions) are the same as my answer.