There are a few you can choose from:
Statistics and probability
Geometry
Proofs
Triangles
Circles
Numerical sequences
Number Theory
etc.
SA = 2
+2

1. Find the radius.
R = 1/2D
6 x 1/2 = 3
R = 3
2. Plug them in.
SA 2(3.14)(3)(7) + 2(3.14)(3^2)
3. Solve
3 x 7 = 21
21 x 3.14 = 65.94
65.94 x 2 = 131. 88
3^2 = 9
9 x 3.14 = 28.26
28.26 x 2 = 56.52
4. Add them together.
131.88 + 56.52 = 188.4
Answer: 188.4 square millimeters
By drawing the hypotenuse of the shape.
u have to work more hard ☺️☺️☺️