Do you means array of number (integer))? If so, perhaps your array should be look like this in C/C++:

int num[5][5] =
{
{ -1, 12, 23, 4, 15 },
{ 16, 57, -8, 19, 0, },
{ 14, 22, -13, -14, 55 },
{ 10, 0, 2, 1, 20 },
{ 11, 22, -23, 14, 96 }
};

This is a 5x5 array of int, To determine the minimum value of 3rd row, you can use this loop:

int i, a, b;

a = num[2][0];
for (i = 1; i < 5; i++) {
b = num[2][i];
if ( a > b)
a = b;
}

after the loop end, the minimum value is now stored in a, and so with to find maximum value in a column, just change the row index and a more than '>' to less than '>'. Remember that C/C++ array always indexed from 0.

a = num[0][1];
for (i = 1; i < 5; i++) {
b = num[i][1];
if (a > b)
a = b;
}

Unfortunately i don't understand with 'triangle', but i hope this example give you a point to start.... AND I CAN'T WRITE CORRECT CODES HERE because it maybe re-formatted by this text-form.

Hi Ardhan Madras ..and thanks for your answer .but when i try to run this program"with the Code Blocks compiler" an error message appears pointing to the statement
b=num[2]; saying that{ invalid conversion from int * to int}
so why is that? also there must be 2 loops instead of one ?

Why does this sound an awful lot like a homework assignment?