Answer:
Step-by-step explanation:
Since area of a circle is pi.r^2
We know that diameter is 20
Radius is half of diameter
So it becomes
Pi.(d/2)^2
So pi.(40/4) is the area of this circle.
Or 40pi/4
Answer:
3) 1 5/6 mi
4) a. 4 cm, 6 ft
b. 6.4 cm, 9.6 ft
c. same as part a
Step-by-step explanation:
3) Each of the given distances appears twice in the sum of side measures that is the perimeter. Hence by walking the perimeter twice, Kyle walks each of the given distances 4 times. His total walk is ...
4×1/3 + 4×1/8 = 4/3 + 4/8
= 1 1/3 + 1/2 = 1 2/6 + 3/6
= 1 5/6 . . . . . miles
___
4) Since the figure is rectilinear (all angles are right angles, and all sides are straight lines), the sum of partial dimensions in one direction is equal to the whole dimension in that direction.
a. 8 cm = 4 cm + x
8 cm - 4 cm = x = 4 cm
The distance in the room is ...
(4 cm)×(1.5 ft/cm) = 6 ft
b. 10.3 cm = 3.9 cm + y
10.3 cm - 3.9 cm = y = 6.4 cm
The distance in the room is ...
(6.4 cm)×(1.5 ft/cm) = 9.6 ft
c. The answer to part b was obtained in the same way as the answer to part a. The unknown dimension is the difference of given dimensions. The actual length in the room is the model length multiplied by the inverse of the scale factor.
