Browse · harp
Printimc
geometry intermediate
Problem
Let be a rectangle with and . Point and lie on and respectively so that all sides of and have integer lengths. What is the perimeter of ?
(A)
(B)
(C)
(D)
Solution
We know that all side lengths are integers, so we can test Pythagorean triples for all triangles. First, we focus on . The length of is , and the possible (small enough) Pythagorean triples can be are where the length of the longer leg is a factor of . Testing these, we get that only is a valid solution. Thus, we know that and . Next, we move on to . The length of is , and the small enough triples are and . Testing again, we get that is our triple. We get the value of , and . We know that which is , and which is . is therefore a right triangle with side length ratios , and the hypotenuse is equal to . has side lengths and so the perimeter is equal to
Final answer
A