Answer:
1. 16(pi)
2. 20.25(pi)
3. 30
4. 4
Step-by-step explanation:
1.
The formula for the are of a circle is ([tex](pi)(r)^2[/tex]) where (pi) represents (3.1415), and (r) represents the radius or the distance from the center to the outer part of the circle. Substitute in the given values and solve,
[tex](pi)(4)^2\\\\16(pi)[/tex]
2.
One can use a similar technique to find the area of the circle in the second problem. Only that the diameter of this circle is given. By its definition, the radius is always half of the diameter, thus one can substitute in the values and solve:
[tex](pi)(\frac{9}{2})^2\\\\(pi)(4.5)^2\\\\(pi)(20.25)[/tex]
3.
When working with scaled representations versus their real counterpart, to go from the scaled representation to the real counterpart, one must multiply by the scale factor.
(6)(5)
= 30
4.
When one would like to go from the real subject to the scaled representation, one will divide by the given scale factor.
(20)/(5)
= 4
