#6. Area grows as the square of the scale
Since the larger pyramid is 2 times as big, its area is 4 times as big: 360 in^2
#7 Volume changes as the cube of the scale.
1/2 the width, 1/8 the volume: 30 ft^3
The first 5 are all ok (except for the units on some).
Hi, I was just wondering if someone could check my answers!
1. Find the surface area of a sphere with a radius of 8 cm.
A.267.9 cm
B.803.8 cm**
C.2143.6 cm
D201.0 cm
2. Find he surface area of a sphere with a diameter of 12 m.
A. 452.2 m**
B.150.7 m
C.113.0 m
D.904.3 m
3. Find the volume of a sphere with a radius of 4 ft.
A.33.5 ft
B.67.0 ft
C.267.9 ft**
D.803.8 ft
4. For the pair of similar solids, find the value of the variable. (Shown below is two similar cylinders, one with a height of 6 and radius of 15 and another with an unlisted height and a radius of 5)
A.3 cm
B.18 cm
C.16 cm
D.2 cm**
5. For the pair of similar solids, find the value of the variable. (Shown bellow are two similar pyramids, one with an unlisted base measurement and slant height 24 and one with a base measurement of 4 and a slant height of 8.)
A.12 mm**
B.48 mm
C.20 mm
D.3 mm
6. A pyramid had a height of 5 in. and a surface area of 90 in. Find the surface area of a similar pyramid with a height of 10 in. Round to the nearest tenth, if necessary.
A.360 in
B.180 in**
C.22.5 in
D.3.6 in
7. A rectangular prism has a width of 92 ft and a volume of 240 ft. Find the volume of a similar prism with a width of 46 ft. Roud to the nearest tenth, it necessary.
A.30 ft
B.40 ft
C.60 ft
D.120 ft**
I'm rather confident about them but, if I made any mistakes, it would be nice to know!
3 answers
Thank you so much!
1. Your choice is off by about 1 cm, but it is the closest choice
2. yes
3. yes, what are you using for π? Most calculators have an good accurate approximation
4. yes
5. yes
6. no, the surface areas are proportional to the squares of their corresponding sides, so
10^2/5^2 = x/90
4 = x/90
x = 360
7. no, the volumes ..... proportional .... to the cubes of their sides, so
92^3/46^3
= 2^3 = 8
So the new volume is 1/8 of 240 or 30 ft
2. yes
3. yes, what are you using for π? Most calculators have an good accurate approximation
4. yes
5. yes
6. no, the surface areas are proportional to the squares of their corresponding sides, so
10^2/5^2 = x/90
4 = x/90
x = 360
7. no, the volumes ..... proportional .... to the cubes of their sides, so
92^3/46^3
= 2^3 = 8
So the new volume is 1/8 of 240 or 30 ft
7 answers