ledger list
Ab&cd two chord meet at o not at centre.tangents drawn from point a&c meet point p and tangents drawn from point b &d meet at point q.toprove angleapc+anglebqd=2angleboc
how to solve unknown variables in triangles such as x, y, z
Find the angel between two straight lines y=m1x+c1&y=m2x+c2
ydx+2(y4-x)dy=0