Hey, I need some help with quite challenging maths exercises. The solutions of how to find those would be very needed, because my mind is close to blowing up .

Cilinder height is 2 m and bottom radius is 7 m. Inside the cilinder is a square, which is inclined by the axis and its corners are located on both bottom circles. Find the square side length. (I literally have no clue on where to even start here)

Cone height is 10 cm and bottom area is 25 π square-cm. Find the area of the section which is parallel with the bottom, if the section is 4 cm away from the bottom of the cone. (I found the bottom radius with 25 π=πr² and the r=5cm. With the pythagoras I found the side of the triangle which came as √125(cm). From that point I am stuck)

Triangles sides are 12 cm, 17 cm and 25 cm and its spinning around its closest side. Find the area of the new object. (I tried to use Heron formula, but I have no clue what to continue with there)

If pictures of solutions cant be put here, I would be grateful to death if you sent them to me at my email: andreandyb@gmail.com

Thanks in advance and have a wonderful day!