Step-by-step explanation:
a rectangular prism (like this brick) has the same basic structure as a cube (like a die) : it has 6 sides.
while a die has 6 equal sides, a rectangular prism has 3 pairs of equal sides :
top and bottom
left and right
front and back
all we have to do is calculate the areas of the 6 rectangles and add them up. that's it.
your remember, the area of a rectangle is
length × width
in our case we have
top and bottom : 2.5×11.5 × 2 = 28.75×2 = 57.5 in²
left and right : 2.5×5 × 2 = 12.5×2 = 25 in²
front and back : 11.5×5 × 2 = 57.5×2 = 115 in²
so, the total surface area of the whole block is
57.5 + 25 + 115 = 197.5 in²
X is the number of hours studied, so replace x with 3 in the equation:
y = 6.8(3) + 60
y = 20.4 + 60
y = 80.4
Round down to 80.
The answer would be A.
Answer:
72 hours
Step-by-step explanation:
1hour30minutes times 48 cars (since TWO pass every 1:30, not one)
equals 72 hours, or three days
Answer:
(C)
Step-by-step explanation:
Given the distance, d(t) of a particle moving in a straight line at any time t is:
To find an expression for the instantaneous velocity v(t) of the particle at any given point in time, we take the derivative of d(t).
The correct option is C.
Answer:
DE ≈ 14.91
Step-by-step explanation:
Make use of the relationships between sides and angles in a right triangle. These are summarized by the mnemonic SOH CAH TOA:
Sin = Opposite/Hypotenuse
Cos = Adjacent/Hypotenuse
Tan = Opposite/Adjacent
__
The side DE is opposite the angle 19°, so the sine or tangent relation will be involved. The sine relation requires you know hypotenuse EF. The tangent relation requires you know adjacent side DF.
The only common side between triangles CDF and DEF is side DF. That side is opposite the given 61° angle. The given side length (CF = 24) is adjacent to the 61° angle.
This means you have enough information to use these relations:
tan(61°) = DF/CF = DF/24
DF = 24·tan(61°)
and
tan(19°) = DE/DF
DE = DF·tan(19°) = (24·tan(61°))·tan(19°) . . . . . use DF from above
DE ≈ 24(1.804048)(0.344328) ≈ 14.908
The length of DE is about 14.91.
