Step One
Develop a formula for the perimeter.
Argument
What you see is a semicircle going upwards and another one going downwards. Two semicircles =1 circle.
The "perimeter" [Circumfrence] of a whole circle = 2*pi*r
We are told that whatever you call this the perimeter is 8pi + 16
Step Two
Set up the equation
8pi + 16 = 2*pi*r + 4r Including the line connecting these two.
Step Three
Take out the common factors on the left and right.
8(pi + 2) = 2r(pi + 2) Divide both sides by pi + 2
8 = 2r Divide by 2
4 = r
Sorry. I didn't know the meaning of perimeter. Mathmate is perfectly correct.
Step-by-step explanation:
since we are using Pythagoras
c² = a² + b²
with c being the Hypotenuse (the baseline opposite of the 90° angle),
you want to get the expression
y² = 3² + 3²
so, you pick the ² and put it next to the y left of the "=" sign.
and to the right of the "=" sign you put 3, ², +, 3, ²
Answer:
C
Step-by-step explanation:
Find the surface area:
Bottom base: 57 × 27 = 1,539
Top base: 21 × 27 = 567
Rectangular face: 23 × 27 = 621
Rectangular face: 23 × 27 = 621
Trapezoidal face: (21 + 57) ÷ 2 × 15 = 585
Trapezoidal face: (21 + 57) ÷ 2 × 15 = 585
1,539 + 567 + 621 + 621 + 585 + 585 = 4,518
The surface area is 4,518 square inches
8.473 is the correct answer
