Bradford T. answered 01/15/21
Retired Engineer / Upper level math instructor
The diagonals are bisected. All diagonals are equal since SQRE is a square. All half diagonals are equal.
a) ST = 2x+3 = EQ/2 = (6x-11)/2
2x+3 = 6x-11
14 = 4x
x = 14/4 = 7/2
EQ = 6x-11 = 6(7/2)-11 = 21-11 = 10
b) All the angles at point T are 90°. There is probably some geometry theorem that shows that. But, since SQRE is a square, bisected corner angles are 45°. So 45 +45 +x = 180, x = 90.
m∠ETS = 90 = 3w-z
m∠ERQ = 90 = w-2z Since ∠ERQ is a corner of a square.
w = 90+2z
Substitute w into the first equation
90 = 3(90+2z)-z = 270 +6z -z = 270+5z
5z = 90-270 = -180 --> z = -36 and w = 90 + 2(-36) = 18
z = -36 and w = 18