Question

I need help! A flagpole casts a shadow 25 feet long and the angle of elevation of the sun is 72 degrees. Find the height of the flagpole to the nearest foot.

Answer 1

From the diagram you can see that we have constructed a right triangle, with height A and base 15.Length of shadow = 15 feet.Height of flagpole = A.We know the angle of elevation is 40∘. Using this angle and the tangent ratio, we can find A.tan(40∘)=oppositeadjacent=A15∴tan(40∘)=A15Rearranging:A=15tan(40∘)By calculator:A=12.59 feet. ( 2 d.p.)