Answer:
12
Step-by-step explanation:
ΔBAD is similar to ΔCBD. So we can write a proportion:
BD / CD = AD / BD
h / 16 = 9 / h
h² = 144
h = 12
Step-by-step explanation:
6. 7. 13
18. 10. 28
24. 17. 41
Log25 (5•25) = 3 over 2 aka 3/5
Your friend's distance from her starting point to your position is decreasing until she passes by you. This distance is D(t) = 100 ft - (20 ft / sec)t. We'll assume that your friend doesn't actually pass by you; she just gets closer and closer, from her initial 100 ft distance from you. Then:
D(t) = 40 ft = 100 ft - (20 ft / sec)t. Simplifying, we get:
-60 ft = -(20 ft / sec)t, and thus t = 3 sec.