Please help me on this problem !

8.485

Step-by-step explanation:

This is a right isosceles triangle, thus the angles for side a and b are going to be the same, all the angles must all add up to equal 180, thus 180 - 90 = 90 then 90 ÷ 2 = 45 so we now know that angle a and b are 45°, with that said we can now find out what the vale of x is.
Calculates 2 sides based on 3 given angles and 1 side.

a = c·sin(A)/sin(C) = 8.48528 = 6

b = c·sin(B)/sin(C) = 8.48528 = 6

Area = = 36

Perimeter p = a + b + c = 28.97056

Semiperimeter s = = 14.48528

Height ha = = 8.48528

Height hb = = 8.48528

Height hc = = 6

Median ma = = 9.48683

Median mb = = 9.48683

Median mc = = 6

Inradius r = = 2.48528

Circumradius R = = 6

answer: the common difference is -0.10

i would need to see the dot plot : )