A boat leaves the dock and sails in a direction of 70°. Once reaching its destination on the opposite shore, it sails in a direction of 272° and docks 150 km north of its original starting position. What is the total distance the boat has traveled?
Name:
Anonymous2009-07-29 21:00
READ SICP
Wait, wrong board, sry.
Name:
Anonymous2009-07-29 21:24
Draw this as you read or you will get lost. draw two parallel lines. draw a diagnol and mark the angle 70deg. from the top line, draw a 272deg circle then go all the way back the first line. You just made a triangle. Now find the angles for the 3 that you just made. Because you made a 272deg angle initially, you know the angle to the right is 80 degrees. because you made two parallel lines, you know that the angle to the left of the triangle is 70deg. 360-70-80=30 so now you know the center angle is 30deg. Since 2 of your angles are 70degs and 30degs, you know that the last one is 80. because you are now 150kms away from your origin, the length of your bottom side is 150km. Now use law of sines to find the rest of the angles. sinA/a = sinB/b = sinC/c. Add up the lengths of the triangle and subtract 150kms.