Explanation:
2.
it is a square !
what do we know about squares ?
first of all, they are a special rectangle, where length = width, and therefore all 4 sides are equally long.
and secondly, as they are a form of rectangle, every inner angle is 90°.
so,
6x - 12 = 90
6x = 102
x = 102/6 = 17
therefore,
CD = x + 15 = 17 + 15 = 32
many greetings to your teacher, CD is a side, a length, and NOT an angle, so it is NOT measured in degrees (°).
since it is a square and all sides are equally long,
AD = CD = 32
3.
it is a rectangle.
so, it has 4 sides consisting of 2 pairs of equally long sides. that means there are 2 equally long side we call length, and 2 equally long sides we call width.
these equally long sides are always opposite of each other.
that means
2x - 52 = x - 2
x - 52 = -2
x = -2 + 52 = 50