Hello, hope this makes some sense, the midpoint formula is what’s given in the picture and the rest is just substitution
Carmen has given 6 coins to her brother<span />
Answer:

There are two best ways to solve this.
using cosine method:




using sine method:




There are many ways, not to make it complex, these are the best ways to solve for n. Hope it helps ~
The distance formula to find the length of the sides... opposite sides equal it could be a rectangle or parallelogram all sides equal, square or rhombus adjacent equal, kite and then the slope is used to check angles if the product of the 2 lines in -1 the lines are perpendicular (right angle) the slopes of 2 lines are the same the sides are parallel. Hope it helps.