Answer:
25000%
Step-by-step explanation:
<h3>Given</h3>
- C(t) = 40 cm + t·(2/5 cm/s) . . . circumference of a circle vs time
<h3>Find</h3>
- dr/dt for radius r
- r at t=4 seconds
<h3>Solution</h3>
The circumference and radius of a circle are related by
... C = 2πr
so the radius in terms of circumference is
... r = C/(2π)
... r(t) = (40 +0.4t)/(2π) = (1/π)(20 cm + 0.2t cm/s)
Then dr/dt is
... dr/dt = 0.2/π cm/s
And the radius at t=4 s is
... r(4) = (1/π)(20 + 0.2·4) cm
... r(4) = 20.8/π cm
The sum of the angles of 4-sided shapes is 360°
To find the missing angle, you can do this:
x + 92° + 47° + 82° = 360° Add 92, 47, and 82 together
x + 221° = 360° Subtract 221 on both sides to get "x" by itself
x + 221° - 221° = 360° - 221°
x = 139° Your answer is the 4th option
