let

x = the first angle

y = the second angle

z = the third angle

since x, y and z are angles of a triangle we have

x + y + z = 180

the second angle of the triangle is 5 more than the first angle

y = 5 + x

the third angle is 19 more than two times the first angle

z = 19 + 2x

by solving the system of equations

x + y + z = 180

y = 5 + x

z = 19 + 2x

we find

x = 39 degrees

y = 44 degrees

z = 97 degrees

the angles of the triangular yard are 39, 44 and 97 degrees respectfully.