Finish your homework easily and quickly with Expert Help and FREE NCERT Solutions
Introductory Video
Select Board
Select Class
By clicking on "SIGN UP" you agree to T&C
Existing user? Login here
Purchase mobileappIcon Download our Mobile App
Call Us at 011-40705070  or  
Click to Call
Select your Board & Class
  • Select Board
  • Select Class
find the measure of each angle of a parallelogram, if one of its angle is 30 degree less than twice of the smallest angle.
Asked by Kirti Maurya(student) , on 5/3/11

Become Expert
Become a Math expert
Start Now with Video Lessons, Sample Papers, Revision Notes & more for Class-IX - CBSE 


Here is the answer to your question.
Let ∠A be the smallest angle of the parallelogram ABCD
∠A = ∠C  (opposite angles of parallelogram are equal)
∠B = ∠D  (opposite angles of parallelogram are equal)
Given, ∠B = 2∠A – 30° 
∠A + ∠B = 180°  (sum of consecutive interior angles is supplementary)
⇒ ∠A + (2∠A – 30°) = 180°
⇒ 3∠A = 210°
⇒∠A = 70
∠B = 2 × 70° – 30° = 140° – 30° = 110°
Thus, ∠A = ∠C = 70° and ∠B = ∠D = 110° 

Posted by Lalit Mehra(MeritNation Expert)on 9/3/11

This conversation is already closed by Expert

Ask a QuestionHave a doubt? Ask our expert and get quick answers.
Show me more questions