5*2x is 10x
5*3y is 15y
5*5z is 25z
Well since the first expression says 8x(40+7) the answer would be 40 that is missing
Since your splitting 47 into 40 and 7 and multiplying both of them by 8 the answer would be 40
It would be right-angled Triangle.
You can check for that, by putting the values into Pythagoras Theorem:
H² = P² + B²
10² = 8² + 6²
100 = 64 + 36
100 = 100
L.H.S = R.H.S
As it obeys Pythagoras theorem, It would be a right-angled triangle only, with two small arms (Base & Perpendicular) and a long arm, opposite to perpendicular (Hypotenuse)!!!
Hope it helped.