幾何與角

In the figure, $ABCDE$ is a regular pentagon. $\angle ADB=$

In the figure, $ABCD$ is a square and $ABE$ is an equilateral triangle. $\angle ADE=$?

In the figure, the two circles intersect at $A$ and $B$. $CAE$ and $CBD$ are straight lines. $\angle CED=$

In the figure, circle $AXB$ passes through the centre of circle $AYB$. $y=$

In the figure, $ABCD$ is a rectangle. $\angle BEF=90^\circ$. Which two of the triangles I, II, III and IV must be similar?

In the figure, the inscribed circle of $\triangle ABC$ touches $AC$ at $D$. If $AB=7$, $AC=5$ and $AD=2$, then $BC=$

In the figure, $AD$ and $BE$ bisect $\angle A$ and $\angle B$ respectively. $\angle C=$

In the figure, $O$ is the centre of the circle and its radius is $r$. $XY$ touches the circle at $P$. Find the distance of $Q$ from $XY$.

In the figure, $AB=BC=CD$. $\angle AED=$

In the figure, $RS$ is a tangent to the circle at $C$. $BA$ is any chord parallel to $RCS$. Which of the chords $AB$, $BC$ and $CA$ must be equal in length?