Chose one of these to solve your question:
sin(D) = EC / X
cos(D) = 12 / X
tan(D) = EC / 12
Point H is an orthocenter in a triangle ABC. All 3 altitudes intersect at point H.
∠BAC + ∠HCA = 90 degrees
What do you not know?!?
I'll give you a tiny hint:
(10x+10)2 = [2(6x-8)]2
Now, you're even more confused
Let ABCD be a parallelogram such that AB = 10, BC = 14, and angle A = 45 degrees Find the area of the parallelogram.
Triangle Angle Bisector Theorem
AX / 28 = 21 / 30
( I'm your guest, but you can trust me)
Height of a triangle is √3 / 2
Diagonal of a large square is 1 + √3
Area = ( 1 + √3 )2 / 2
I guess it's r =?
(1 + r)2 = (2 - r)2 + 12
Using Pythagorean theorem find BD and then AD