In the following two questions, how would I find the solid angle at the origin? 1.Find the solid angle subtended at the orgin by the triangle with corners P=(1,0,0) Q=(0,1,0) and R=(0,0,1). 2.What is the solid angle subtented at the orgin by the plane x+y=4? For the second question, will i start by making x=0 and solve for y. So when x=0 y=4. y=0 x=4 (0,4) (4,0) Then what?