Answer:
25
Step-by-step explanation:
Formula
2xy + 1
Givens
x = 3
y = 4
Solve
2*(3)*(4) + 1
24 + 1
25
Check the slopes
the first 2 points have slope (3-1) / (5-1) = 2/4 = 1/2
points 2 and 3 slope = 4/2 = 2
3 and 4:- slope = -2/-4 = 1/2
4 and 1:- slope = 4/2 = 2
so we have 2 pairs of opposite sides which are parallel
looks like a parallelogram or a rhombus
if adjacent sides are equal its a rhombus
length betwee pts 1 and 2 = sqrt(2^2 + 4^2) = sqrt20
.. ... ... .. .. .. ...2 and 3 = sqrt(4^2 + 2^2) = sqrt20
so it is a rhombus