SOLUTION: In an isosceles trapezoid ABCD, the smaller base is AB, AE and BF are altitudes drawn to side DC. If AE=7ft and DE=8ft, find angle D to the nearest degree. Then find AD using trigo

Algebra ->  Trigonometry-basics -> SOLUTION: In an isosceles trapezoid ABCD, the smaller base is AB, AE and BF are altitudes drawn to side DC. If AE=7ft and DE=8ft, find angle D to the nearest degree. Then find AD using trigo      Log On


   

Question 1106105: In an isosceles trapezoid ABCD, the smaller base is AB, AE and BF are altitudes drawn to side DC. If AE=7ft and DE=8ft, find angle D to the nearest degree. Then find AD using trigonometric ratios. Round AD to the nearest unit.

I got that angle D equals 41 degrees, but I am not sure how to find AD using trigonometric ratios?????
Answer by KMST(5328) About Me  (Show Source):
You can put this solution on YOUR website!
I agree that to the nearest degree D=41%5Eo .
From there, you could use the trigonometric ratios sin%28D%29=AE%2FAD or cos%28D%29=DE%2FAD .
You could say that
sin%28D%29=AE%2FAD
sin%2841%5Eo%29=7ft%2FAD
and using the approximate value sin%2841%5Eo%29=0.656
0.656=7ft%2FAD
0.656AD=7ft
AD=7ft%2F0.656
AD=10.67ft(rounded)
To the nearest unit AD=highlight%2811ft%29 .

The problem makes sense if you are only able to use trigonometric value tables,
just like I did before Hewlett Packard started selling calculators.
With a calculator, you could give your answers with more decimal places,
and you may even be tempted to calculate AD using the Pythagorean theorem, as