(a)Is triangle ABC a right-angled triangle? Justify your answer. [Note: A right-angled triangle is a triangle with one 90o internal angle.] Vector AB is ( 3, 6 , 1) Vector BC is ( 0 , -7 , -4) Vector CA is ( -3 , 1 , 3)
Follow Math Help Forum on Facebook and Google+
Originally Posted by daphnewoon (a)Is triangle ABC a right-angled triangle? Justify your answer. [Note: A right-angled triangle is a triangle with one 90o internal angle.] Vector AB is ( 3, 6 , 1) Vector BC is ( 0 , -7 , -4) Vector CA is ( -3 , 1 , 3) Take the three dot products, see if one of them is 0.
the x part is zero. thus it is a right-angled triangle?
No. Do what I said. Find , and , and see if any of these dot products are 0. If so, you have a right angle. If you do not know anything about dot products (also known as scalar products) I suggest you do a Google search.
View Tag Cloud