Alvin's age + Elga's age = 84
2R + R = 84
3 R = 84
3/ 3 R = 84/ 3
R = 28
Elga's age is 28
The formula for arc length is s=r*angle theta where s is the arc length, r is the radius, and angle theta is central angle formed by the arc in radians.
In this case, the angle would be s/r or 4.2/4 which is 1.05 radians. We have to convert this into degrees and so you would multiply 1.05 by (180/pi) which results in approximately 60 degrees. Remember, if you want to convert radians into degrees, the conversion factor is 180/pi and for degrees into radians, it is pi/180.
Yes, they are proportional because if you increase or decrease either amount they will both change. They will always have the same size. For example if I want to double the flour, I will have to double the milk as well because they have the same ratio.
1.75 + 0.65m < = 10
0.65m < = 10 - 1.75
0.65m < = 8.25
m < = 8.25 / 0.65
m < = 12.69 miles <==
