In rectangle ABCD, corner A is folded over crease DE to point F on BC. Find BC.

Guest Apr 26, 2022

#1**+1 **

We know that \(EF = 9\)

Using the Pythagorean Theorem, \(BF = \sqrt{45}\)

Let \(DF = BC = x\)

We can derive the following equation using the Pythagorean Theorem: \(x^2=225+(x-\sqrt{45})^2\)

Solving, we find that \(\color{brown}\boxed{BC = 3 \sqrt{45}}\)

BuilderBoi Apr 27, 2022