Matrix A has 3 rows, 2 columns
Matrix B has 3 rows, 2 columns
The number of columns in matrix A (which is 2) does not match up with the number of rows in matrix B (which is 3).
So the matrix multiplication A*B is undefined. We cannot multiply the matrices.
The diagram of the triangle is shown below
One interior angle is 56°
One exterior angle is 103° ⇒ we can work out one interior angle 180°-103° = 77°
The other interior angle is 180° - (56°+77°) = 44°
Let x be the 1st number
x + 9 be the second number
Equation:
x + x+9 = 171
Solution:
2x + 9 = 171
2x = 171 - 9
2x = 162
x = 81
x + 9 = 90
81 + 90 = 171
A box (cube) has all equal edges or sides (s), thus the volume (v) of the cube is:

So since each side or edge around is 3 in, then the length around the square bottom of the box = 4×3 = 12 in