Answer:
Step-by-step explanation:
Remark
The diagonal is found by using the Pythagorean Theorem: a^2 + b^2 = c^2. This only works for certain figures. The rectangle is one of them.
Givens
a = 10
b = 8
c = ? This is the length of the diagonal.
Solution
a^2 + b^2 = c^2
10^2 + 8^ = c^2
100 + 64 = c^2
c^2 = 164
√c^2 = √164
c = 12.806