Answer:
2 o'clock
Step-by-step explanation:
Their 'closing speed' is 60 - 50 = 10 km/hr
they have 20 km between them
at closing speed this will take 20 km / 10 km/hr = 2 hours for the cars to meet....this would be at 14:00 or 2 oclock
ΔADB is a right triangle at ∠D
So, AB ⇒ Hypotenuse & AD,DB ⇒ Legs
∴ ![AD = \sqrt{AB^2 - DB^2} = \sqrt{20^2 - 16^2}=\sqrt{400-256} =\sqrt{144} =12](https://tex.z-dn.net/?f=AD%20%3D%20%5Csqrt%7BAB%5E2%20-%20DB%5E2%7D%20%3D%20%5Csqrt%7B20%5E2%20-%2016%5E2%7D%3D%5Csqrt%7B400-256%7D%20%3D%5Csqrt%7B144%7D%20%3D12)
ΔADC is a right triangle at ∠D
So, AC ⇒ Hypotenuse & AD,DC ⇒ Legs
![CD = \sqrt{AC^2 - DC^2} = \sqrt{15^2 - 12^2}=\sqrt{225-144} =\sqrt{81} =9](https://tex.z-dn.net/?f=CD%20%3D%20%5Csqrt%7BAC%5E2%20-%20DC%5E2%7D%20%3D%20%5Csqrt%7B15%5E2%20-%2012%5E2%7D%3D%5Csqrt%7B225-144%7D%20%3D%5Csqrt%7B81%7D%20%3D9)
∴ BC= BD+ DC = 16 + 9 = 25
∴ The perimeter of triangle ABC = AB + BC + CA = 20 + 25 + 15 = 60.
<u>So, The correct answer is option C. 60</u>
I'm sure you asked this 24 hours ago, but it's A.
Answer:
B because the rotation of the wheel doesn't change the angle of the spokes.