How to draw bounding surfaces with Plot3D?

Hi.
I started with Mathematica and have some troubles.

I need to figure bounded by a given surfaces:

z = 0;
z = x;
y = 0;
y = 4;
x = sqrt(25 - y^2)

I try to reproduce that in Mathematica, but makes something wrong and don’t understand how to make it right

In documentation I find Plot3D function and try using it.

f[x_, y_] := 0;
g[x_, y_] := x;
h[x_] := 0;
m[x_] := 4;
b[y_] := sqrt (25 - y^2);

Plot3D[{f[x, y], g[x, y], h[x], m[x], b[y]}, {x, 0, 10}, {y, 0, 4}]

And getting something like this:

My friend gave me this image that he made himself by hand, but I’m not sure how much it is correct, and decided to do the same automatically using Mathematica

You could use RegionPlot3D, but your curves do not appear to bound an enclosed volume.

Thank you, but RegionPlot3D working with predicates. Try it but nothing

RegionPlot3D[
 y >= 0 && y <= 4 && x >= 0 && x <= sqrt (25 - y^2) && z >= 0 && z <= x ,
 {x, -10, 10}, {y, -10, 10}, {z, -10, 10}
]

In Mathematica, Sqrt[x], not, sqrt(x}. Make sure your syntax is correct and the predicate resolves to True or False only.