PRACTICE QUESTIONS CLASSROOM WING

In $∆ABC$, if $\angle A<\angle B<45°$, then $ABC$ is a/an _____ triangle.

In $∆ABC$, if $\angle A=80°$ and $AB=AC$. If $\angle B=k°$, then $k=$ _____.

In a circle, chord $AB$ subtends an angle of $60°$ at the centre and chord $CD$ subtends $120°$, at it. Then which chord is longer?

Find the number of lines symmetry of a regular octagon. Verify it with a neat diagram.

In the figure below (not to scale), $ABC$ is a straight line. If $\angle FBE=60°, \angle CBG=120°, \angle ABG=x°$, $\angle ABF=\gamma °$ and $\angle CBE=z°=2\gamma °$, then $\left(x°+z°\right):y°$ is

In the figure below, $\overline{EF}\left|\right|\overline{GH}$. If $\overline{GI}$ is the transversal, $\angle IGH=y°$ and $\angle FIG=3y°$, then the ratio of the supplement of $y$ to its complement is

In the figure below (not to scale), $\overline{CD}\left|\right|\overline{RS}, \angle EMG=90°$, $\angle GMD=y°, \angle CME=x°$ and $y°=\frac{x°}{2}$. Then, $\angle FNS:\angle FNR$ is

In the figure below, $CD$ is a chord of the semi-circle with centre $O.$

$OA$ is the radius of the circle. If $CD=10$ cm, $AB=2$ cm and $\overline{OA}\perp \overline{CD}$, then the length of $OB$ is _____.