Angles and sides funny!!
In the above given figure find
angle EDF
.Given that E and F are mid points. ,
AB ,AC, BC
are 5,4 and 7 units respectively.(Take
)
The answer is 101.54.
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
1 solution
Clearly you can draw two circles with E and F as centres[ mid point of hypotenuse is circumcentre ]. So AE=DE and AF=DF. ALSO angle EAD=EDA and angle FAD=FDA[angles opposite to equal sides are equal].
Hence, Angle BAC=EDF. Use cosA in triangle ABC which comes out to be 5 − 1 . angle EDF= cos − 1 ( − 1 / 5 ) = 1 8 0 o − sec − 1 5