Answer:
Surface area = 663π in².
Volume = (676/3)π in² ≈ 225.33 π in²
Explanation:
1) We know the radius and the lateral area.
2) With the radius you can find the areas of the top and the bottom.
For that, you use the formula:
area of the top = area of the bottom = π r²
∴ π (13 in)² = 169π in² (each)
3) Then, the surface area is the sum of the lateral area and the two bases (top and bottom)
surface area = lateral area + bottom area + top area = 325π in² + 2×169π in² = 663π in².
3) You can also find the height of the cylinder.
Use the formula: lateral area = 2π r h
∴ h = lateral area / [2 π r]
⇒ h = 325 π / [ 2π (13) ] = 12.5 in
4) With the height you can find the volume.
Use the formula: V = (4/3) π r³
∴ V = (4/3) π (13 in)³ = (676/3)π in² ≈ 225.33 π in²
The length of the KN is 4.4
Step-by-step explanation:
We know from Pythagoras theorem
In a right angle ΔLMN
Base² + perpendicular² = hypotenuse
²
From the properties of triangle we also know that altitudes are ⊥ on the sides they fall.
Hence ∠LKM = ∠NKM = 90
°
Given values-
LM=12
LK=10
Let KN be “s”
⇒LN= LK + KN
⇒LN= 10+x eq 1
Coming to the Δ LKM
⇒LK²+MK²= LM²
⇒MK²= 12²-10²
⇒MK²= 44 eq 2
Now in Δ MKN
⇒MK²+ KN²= MN²
⇒44+s²= MN² eq 3
In Δ LMN
⇒LM²+MN²= LN²
Using the values of MN² and LN² from the previous equations
⇒12² + 44+s²= (10+s)
²
⇒144+44+s²= 100+s²+20s
⇒188+s²= 100+s²+20s cancelling the common term “s²”
⇒20s= 188-100
∴ s= 4.4
Hence the value of KN is 4.4