Can someone check my answer ?

quadrilateral abcd is inscribed in circle o.
what is m∠b?

m∠a + m∠b = 180°
2x - 7 + 2x + 3 = 180
4x - 4 = 180
4x = 184
x = 46

m∠b = 2x + 3
m∠b = 2(46) + 3
m∠b = 92 + 3
m∠b = 95°

Nope.
The angles A and B do not add to 180°. Rather angles A and C add to 180°, because the sum of the measures of the arcs they intercept is 360°.
.. (2x -7) +(x+4) = 180
.. 3x = 183
.. x = 61

Then ∠B = (2*61 +3)° = 125°


∠A = (2*61 -7)° = 115°
∠C = (61+4)° = 65°
∠D = 180° -125° = 55°
so ABCD is NOT a trapezoid..

The volume of any prism is just the area of the base times the height of the prism.

The base of the prism is a triangle, and you should know how to find the area of a triangle already. The base is 9, the height is 4, .

Multiply that by the height of 9.5 and we get