can someone provide a youtube video that explains problems like these | Mathematics | Page 1

an isosceles right triangle has 2 angles the same, 1 angle as 90° and 2 sides of the same length.

first you can confirm that 2 sides are the same length with the following |(-4,1)-(-2,-3)|=|(-2,4)|=√20
|(-4,1)-(2,-1)|=|(-6,2)|=2√10
|(-2,-3)-(2,-1)|=|(-4,-2)|=√20, so yes we have 2 sides same length.
Pythagoras only works for triangles with a right angle within them, so you do √20²+√20²=c²
20+20=40, √40=2√10, therefore JEN is an isosceles right triangle.

for those 4 points to form a rectangle, all 4 vertices must be right angles, to prove that it is not a rectangle you need to find a counterexample (where they don't meet at a 90° angle)
(-2,2)-(6,5)=(-8,-3)
(6,5)-(4,0)=(2,5)
(4,0)-(-4,-3)=(8,3)
(-4,-3)-(-2,2)=(-2,-5)
now for lines to be parallel their slope must be the negative reciprocal of eachother, so if we take (-8,-3) and (8,3) and calculate the slope with the formula rise/run or ∆y/∆x then we get 3/8 for both of them, so they are parallel, similarly for the other 2 vectors

#can someone provide a youtube video that explains problems like these