Step-by-step explanation:
we have to solve 2 right-angled triangles via Pythagoras
c² = a² + b²
with c being the Hypotenuse (the side opposite of the 90° angle).
one triangle is 37, 12 and the longer part of the long diagonal.
the second triangle is 13, 12 and the shorter part of the long diagonal.
the whole diagonal is then the sum of both parts.
37² = 12² + longer part²
1369 = 144 + longer part²
longer part² = 1225
longer part = 35
13² = 12² + short part²
169 = 144 + short part²
25 = short part²
short part = 5
so, the total diagonal is 35 + 5 = 40 units.
