Question

If these two triangles in the figure are congruent by ASA criteria, then find the length DE in terms of cm.

• A. 7

Answer 1

The correct option is A 7
In the given figure,
$\angle$ABC = $\angle$DEF = ${60}^{\circ }$
$\angle$BAC = $\angle$EDF = ${30}^{\circ }$
Length of AB = 7 cm

Thus, AB = DE
[As both the triangles are $\cong$ to each other by ASA]

$\therefore$ Length of DE = 7 cm

[ In ASA criteria, the side is included between the two angles and in this given figure, $△$ ABC, the included side is AB as $\angle$A and $\angle$B is given and in $△$ DEF, DE is the included side between both the $\angle$D and $\angle$E. Thus, AB = DE]