Percentage width in a RelativeLayout

Question

I am working on a form layout for a Login Activity in my Android App. The image below is how I want it to look like:

Answer 1

Update

As pointed by @EmJiHash PercentRelativeLayout and PercentFrameLayout is deprecated in API level 26.0.0

Consider Using ConstraintLayout

Google introduced new API called android.support.percent

1)PercentRelativeLayout

2)PercentFrameLayout

Add compile dependency like

compile 'com.android.support:percent:23.1.1'

You can specify dimension in percentage so get both benefit of RelativeLayout and percentage