3 meters = 300 cm
300 cm + 35 cm = 335cm
Each cm is 10mm
So 335 cm = 3350 mm
We can parameterize this part of the cylinder using

with

and

. Then the surface element is


so the area is given by the surface integral, where

denotes the part of the cylinder in question,

Probably less work would involve a simpler geometric approach, but it doesn't hurt to practice setting up a proper surface integral.
Answer:
Not really
Step-by-step explanation:
NOT NECESSARILY would a triangle be equilateral if one of its angles is 60 degrees. To be an equilateral triangle (a triangle in which all 3 sides have the same length), all 3 angles of the triangle would have to be 60°-angles; however, the triangle could be a 30°-60°-90° right triangle in which the side opposite the 30 degree angle is one-half as long as the hypotenuse, and the length of the side opposite the 60 degree angle is √3/2 as long as the hypotenuse. Another of possibly many examples would be a triangle with angles of 60°, 40°, and 80° which has opposite sides of lengths 2, 1.4845 (rounded to 4 decimal places), and 2.2743 (rounded to 4 decimal places), respectively, the last two of which were determined by using the Law of Sines: "In any triangle ABC, having sides of length a, b, and c, the following relationships are true: a/sin A = b/sin B = c/sin C."¹