Answer:
C
Step-by-step explanation:
Yes, ACD = BCD by AAS since they have 2 congruent angles & share a side.
Answer:
t=2.08 seconds.
Step-by-step explanation:
Well, in this example, H(t)=-0.6cos(2pi/2.5)t+1.5 should be equal to 1.2. If calculated, -0.6cos(0.8pi)t=1.2-1.5 which is equal to -0.6cos(0.8pi)t=-0.3, then cos(0.8pi)t=0.5. The value of cosine in terms of radians when it is equal to 0.5 is pi/3. So, cos(0.8pi)t=cos(pi/3). If simplified, (0.8pi)*t=5pi/3. pi's are cancelled out and t is calculated as 2.08333... If rounded to the nearest hundredth it is 2.08.
<em>Formula:</em>

<em>Plug in the values:</em>

<em>Simplify LHS:</em>

<em>Multiply by 1936 on both sides:</em>

<em>Simplify RHS:</em>

<em>Square root both sides:</em>
Answer: The radius is 4 units. (Answer B)