Line BC is tangent to point A at C. If AC = 4 and BA = 5, find BC. Please show how to find this. Thanks!
is point A the center? if so, it forms a right angle when it intersects with the tangent at the circumference. (this is again, the famous 3-4-5 triangle, we know the answer will be 3, but how to find that for certain?)
by Pythagoras' theorem:
(BC)^2 = (AB)^2 - (AC)^2 = 5^2 - 4^2 = 25 - 16 = 9
=> BC = sqrt(9) = 3 ......as expected
if A is not the center, well, i don't know
I think Jhevon is correct
If BC is a tangent to A that means it = 90 degrees
we are given the length of two sides therefore pythagoras theorem can be used
so Jhevon's answer of 3 is correct according to me
maybe you told him to work out the wrong thing?
what's point D for?