Prove that the line of centers of two intersecting circles subtends equal angles at the two points of intersection

In the figure (not to scale) AB = CD, angle DAP = angle DPA and A,B,C,D are concycli. If angle ADC = 80°, then find angle ACD.

Solve : 2^(x+2)+2^(x-1)=9

Volume of a Cylinder

What length of tarpaulin 3m wide will be required to make conical tent of height 8m and base radius 6m ? Assume that the extra length of material that will be required for stitching and wastage in cutting is approximately 20cm ( Use pi= 3.14)

Find the square of: 2a +b