Answer:
62 square units
Step-by-step explanation:
The area of a rectangular prism is the sum of the areas of its six faces. Opposite faces have the same area, so it is the sum of 3 pairs of faces. The area of one face of each pair is the product of the dimensions of that face. Those three areas are ...
• L·W
• W·H
• H·L
so the total surface area is ...
A = 2(LW +WH +HL)
For hand calculation, this can be simplified a bit to ...
A = 2(LW +H(L+W)) . . . . . requires one less multiplication
For your prism, the area is ...
A = 2(5·2 + 3(5+2)) = 2(10 +21) = 62 . . . square units
Answer:
remaining cardboard area = 122.5πr²
Step-by-step explanation:
area of original rectangle = length * width
= 18r * 8r
= 144r²
- area of semi circle:
πr²
Here we have 3 semi circles with radius 3r:
- area of 3 semi circles: 3(
* π * (3r)²)
: 3(
* π * 9r²)
: 13.5πr²
- area of one semi circle with radius 4r:
(
* π * (4r)²)
(
* π * 16r²)
8πr²
- So the area of remaining cardboard:
area of rectangle - area of 4 semi circles
144r² - 13.5πr² - 8πr²
122.5πr²
Answer:
x ≈ 17.1 m
Step-by-step explanation:
Using Pythagoras' identity in the right triangle
x² = 9² + 14.5² = 81 + 210.25 = 291.25 ( take the square root of both sides )
x =
≈ 17.1 m ( to 1 dec. place )
I'd suggest you look up "deciliter." If you do, it should be obvious whether 3.78 liters is greater than or less than 3.78 liters.
What if the question involved "ft?" Which would be larger, 1 foot or 1 inch?