4. Find the HCF and LCM of 45 and 75 using prime factorisation.​

HCF: 15 / LCM: 225

Step-by-step explanation:

The factors of 45 are: 1, 3, 5, 9, 15, 45

The factors of 75 are:  1, 3, 5, 15, 25 75.

The highest factor they share in common is 15 (HCF).

Multiples of 45: 45, 90, 135, 180, 225

Multiples of 75: 75, 150, 225, 300, 375

The lowest multiple they share in common is 225 (LCM).

18

step-by-step explanation:

draw the shape and you will see that f and k are actually at adjacent vertices (points of the hexagon that are neighboring).   so find the distance between (1,2) and (4,2).   that is easy since (1,2) and (4,2) is just a vertical distance to count, which is 3.   it is a regular polygon which means all sides are congruent.   you have 6 sides (hexa) so multiply 6 by 3 to receive 18.