The triangle on the left is a 45 45 90 triangle and the triangle on the right is a 30 60 90 triangle.
In a 45 45 90 triangle, the length of the hypotenuse is equal to the length of either one of the legs times the square root of 2. So that means that a and c are both 18.
In a 30 60 90 triangle, the length of the hypotenuse is twice that of the leg opposite the 30 degree angle. So that means that b is 36. The length of the leg opposite the 60 degree angle is the length of the other leg times the sq root of 3. So that would give you d = 18 sq root 3.