How to Decrease the size of radiobutton in android

I have designed an activity in which i have two radio button
but those size are more than enough i want to decrease it
i am using text size that decreases only text
if layout size is decrease that decrease only view not radio button circle

<RadioGroup
           android:id="@+id/RG1"
           android:layout_width="wrap_content"
           android:layout_height="wrap_content"
           android:orientation="horizontal" >

           <RadioButton
               android:id="@+id/N"
               android:layout_width="wrap_content"
               android:layout_height="70dip"
               android:text="Yes"
               android:textSize="12dip" />

           <RadioButton
               android:id="@+id/Y"
               android:layout_width="wrap_content"
               android:layout_height="70dip"
               android:checked="true"
               android:text="No"
               android:textSize="12dip" />
       </RadioGroup>

Tags: Mobile Apps (Android), Checkbox