Question

In this diagram measurement angle ADB=90 degree, measurement angle DBC=45 degree and BC =10 meter then find out the AB=?? Please solve this question ​

Answer 1

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$\large \tt \red{✦Answer✦}$

Given : AB = 12 cm. BC = 6.5 cm.

In the ΔABC, ∠ABC = 90°.

Since AD = DC, D is the midpoint of AC.  So BD is the median.

AB ⊥ BC.

\begin{gathered}\text{Area of }\Delta ABC = \frac{1}{2}\times BC\times AB\\\\Area =\frac{1}{2}\times 6.5\times 12=39\text{ cm}^2\end{gathered}

Now, since BD is the median it divides the ΔABC into two equal parts.

2 × Ar(ΔADB) = Ar(ΔABC) 

⇒ 2 × Ar(ΔADB) = 39

⇒ Area of ΔADB = 19.5 cm²

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