幾何與角

In the figure, $ACD$ and $ECB$ are straight lines. If $\angle EAC=\angle CAB$ and $EA=EB$, find $x$.

In the figure, $ABCDE$ is a regular pentagon and $ABFG$ is a square. Find $x$.

In the figure, $AEB$ and $ADC$ are straight lines. Find $ED$.

In the figure, $AT$ is tangent to the circle at $T$ and $ABC$ is a straight line. Find $AT$.

In the figure, $ABCD$ is a rectangle. $M$ is the midpoint of $BC$ and $AC$ intersects $MD$ at $N$. Area of $\Delta NCD$ : area of $ABMN=$

In the figure, $AB$ is a diameter of the circle and $ABD$ is a straight line. $\angle CBD=$

In the figure, $AD$ is a diameter of the circle. If $\widehat{AB}:\widehat{BC}:\widehat{CD}=3:5:7$, then $\angle ADC=$

In the figure, $AB=BC=CA=CD$. Find $\angle CBD$.

In the figure, $ABCD$ is a trapezium. Which of the following must be true? I. $AED$ is an equilateral triangle. II. $EBCD$ is a parallelogram. III. $AB=2DC$

In the figure, $CE$ is tangent to the circle at $C$. Find $\angle DCE$.