So there is two congruent right angle triangles and the distance from the centre of the earth to the satellite is the 6360+720= 7080km And the radius of the earth is the 6360 which forms one of the other sides of the triangle. So the only missing part is BA so BA = the square root of 7080² - 6360² which equals about 3110.76KM So BC= 3100 rounded to nearest hundredth which it asks you to in the question
