Answer:
The proof is explained below.
Step-by-step explanation:
Given m∠ADB = m∠CDB and AD ≅ DC
we have to prove that m∠BAC = m∠BCA and BD⊥ AC
In ΔADO and ΔCDO
∠OAD=∠OCD (∵ADC is an isosceles triangle)
AD=DC (∵Given)
∠ADO=∠CDO (∵Given)
By ASA rule, ΔADO≅ΔCDO
In ΔBAD and ΔBCD
AD=DC (∵ABC is an isosceles triangle)
∠ADB=∠CDB (∵Given)
DB=DB (∵common)
By ASA rule, ΔADB≅ΔCDB
Now, ΔADB≅ΔCDB and ΔADO≅ΔCDO
⇒ ΔADB-ΔADO≅ΔCDB-ΔCDO
⇒ ΔABO≅ΔCBO
Hence, by CPCT, m∠BAC = m∠BCA
Now, we have to prove that BD⊥ AC i.e we have to prove m∠BOA=90°
Now, ΔABO≅ΔCBO therefore by CPCT, m∠BOA = m∠BOC
But, m∠BOA + m∠BOC=180° (linear pair)
⇒ m∠BOA + m∠BOA=180°
⇒ 2m∠BOA=180° ⇒ m∠BOA=90°
Hence, BD⊥ AC
Answer:

Step-by-step explanation:
GIVEN : In ΔPQR
S is the mid point of QP
U is the mid point of PR
T is the mid point of QR
Solution :
i) is true i.e 
Refer the attached file
By mid segment theorem i.e. In a triangle, the line joining the midpoints of any two sides will be parallel to the third side and that same line joining the midpoints is also half of length of third side .
UT is the line joining the two mid points . So, by theorem given above UT is parallel to PQ and 1/2QP=UT.
So, (i) statement is true i.e. 
Answer:
B) equilateral...............
Answer: option B. 2/11
Explanation:
1)
number of positive outcomes
Probability = ------------------------------------------
number of possible outcomes
2) Number of positive outcomes:
The positive outcome is choosing a T, given that there are two Ts, the number of positive outcomes is 2.
3) Number of possible outcomes
There are 11 letters, so the number of total outcomes is 11.
4) Therefore,
2
probability = ------
11