question_answer

 

Directions: Q. 16 to 20

Janvi and her father go to meet her friend Sanvi for a candle light event.

When they reached to church. Janvi saw the top of the church which is triangular in shape. If she imagined the dimensions of the top as given in the figure, then answer the following questions.

If D is the mid point of AC, then BD is

A) 2m

B) 3m

C) 4m

D) 6m

Correct Answer: C

Solution :

Given, D is the mid-point of AC.

\[AD=DC=\frac{AC}{2}=\frac{8}{2}=4m\]

\[BD=\sqrt{{{\left( BC \right)}^{2}}-{{\left( DC \right)}^{2}}}\]

[Apply Pythagoras theorem in \[\Delta ACD\]]

\[BD=\sqrt{{{\left( 4\sqrt{2} \right)}^{2}}-{{\left( 4 \right)}^{2}}}\]

\[=\sqrt{32-16}\]

\[=\sqrt{16}m=4\,m\]