Question

If BD is the diameter, then Triangle BCD is Acute,Obtuse,Right. https://media.glynlyon.com/g_geo_2012/7/group177.gif

Answer 1

the measure of <C = 90 deg
so it is right triangle

Answer 2

i think its a right triangle but can you explain why

Answer 3

an inscribed angle subtending the diameter, always be 90 degrees.
this is must be in your book, @iforgot

Answer 4

ok my bad :P
sorries

Answer 5

It is actually a property that the angle is 90°
And can be proved with thales theorem:
http://www.mathopenref.com/thalestheorem.html