HI BABES , SOLVE THIS FOR ME.....WILL MARK UH BRAINLIEST IF YOUR ANSWER IS RIGHT AND PROPER OTHERWISE I'LL REPORT NOT ONLY YOUR ANSWER BUT YOUR PROFILE.
Answers
(i)
In parallelogram ABCD, E is the mid-point of AB.
CE is the bisector of ∠BCD.
⇒ ∠BCE = ∠DCE
⇒ ∠DCE = ∠BEC
⇒ BE = BC
⇒ AE = AD
(ii)
Therefore, ∠ADE = ∠AED [Opposite angles of equal sides are equal.]
But, ∠AED = ∠EDC. [Alternate angles]
⇒ ∠ADE = ∠EDC
⇒ DE is the bisector of ∠D
(iii)
Mark the midpoint of CD as F.
Draw EF parallel to AD.
Let ∠ADE = ∠AED = ∠CDE = x
∠BCE = ∠BEC = ∠DCE = y
∠DEF = x [Alternate angles]
∠CEF = y [Alternate angles]
∠AEB = x + x + y + y = 180°
2(x + y) = 180°
(x + y) = 90°
Therefore, ∠DEC is a right angle
Hope this helps!
Since ABCD is a parallelogram, thenAB∥DC and AD∥BC.Now, CE bisects ∠DCB, so∠DCE = ∠BCE ......(1)Since, DC∥AB and CE is a transversal, then∠DCE = ∠CEB (Alternate interior angles) .....(2)Now, from (1) and (2), we get∠BCE = ∠CEBIn ΔBCE,∠BCE = ∠CEB (Proved above)⇒EB = BC (Sides opposite to equal angles are equal) ......(3)Since E is the mid point of AB, then AE = EB .......(4)We know that opposite sides of ∥gm are equal, thenAD = BC ......(5)Now, from (3), we get EB = BC⇒AE = AD [using (4) and (5)]In ΔDAE, AE = AD ⇒∠EDA = ∠AED [Angles opposite to equal sides are equal] ......(6)Since, DC∥AB and DE is a transversal, then∠EDC = ∠AED (Alternate interior angles) .....(7)From (6) and (7), we get∠EDA = ∠EDC⇒DE bisects ∠ADC.In ΔEDC, ∠EDC + ∠DCE + ∠DEC = 180° [Angle sum property]⇒12∠D + 12∠C + ∠DEC = 180°⇒∠DEC = 180° − 12(∠D + ∠C) ⇒∠DEC = 180° − 12×180° [Adjacent angles of ∥gm are supplementary]⇒∠DEC = 90°