Problem 390
Triangles with non rational sides and integral area
Consider the triangle with sides √5, √65 and √68. It can be shown that this triangle has area 9.
S(n) is the sum of the areas of all triangles with sides √(1+b2), √(1+c2) and √(b2+c2) (for positive integers b and c ) that have an integral area not exceeding n.
The example triangle has b=2 and c=8.
S(106)=18018206.
Find S(1010).
边长为无理数而面积为整数的三角形
考虑边长为√5、√65和√68的三角形,可以算出这个三角形的面积为9。
考虑所有边长为√(1+b2)、√(1+c2)和√(b2+c2)(b和c均为正整数),且面积为不超过n的整数的三角形,记其面积之和为S(n)。
取b=2和c=8即为上述样例三角形。
已知S(106)=18018206。
求S(1010)。