Answer

Step by step solution by experts to help you in doubt clearance & scoring excellent marks in exams.

Updated On: 28-8-2020

Apne doubts clear karein ab Whatsapp par bhi. Try it now.

CLICK HERE

Loading DoubtNut Solution for you

Watch 1000+ concepts & tricky questions explained!

57.0 K+

2.8 K+

Text Solution

Solution :

Let the parallelogram be ABCD, in which `angleADC and angleABC ` are obture angles. Now, DE and DF are two altitudes of parallelogram and angles between them is `60^(@)`. <br> <img src="https://d10lpgp6xz60nq.cloudfront.net/physics_images/ARH_NCERT_EXE_MATH_IX_C08_S01_031_S01.png" width="80%"> <br> Now, BEDF is a quadrilateral, in which `angleBED=angleBFD=90^(@)` <br> `therefore" "angleFBE=360^(@)-(angleFDE+angleBED+angleBFD)` <br> `therefore" "angleFBE=360^(@)-(angleFDE+angleBED+angleBFD)` <br> `=360^(@)-240^(@)=120^(@)` <br> Since, ABCD is parallelogram. ltBrgt `therefore" "angleADC= 120^(@)` <br> Now, `" "angleA+angleB=180^(@)" "` [sum of two cointerior angles is `180^(@)`] ltBrgt `therefore" "angleA=180^(@)-angleB` <br> `5=180^(@)-120^(@)" "[becauseangleFBE=angleB]` ltBrgt `rArr" "angleA=60^(@)` <br> Also, `" "angleC=angleA=60^(@)` <br> Hence, angles of the parallelogram are `60^(@), 120^(@), 60^(@) and 120^(@),` respectively. **What is Quadrilateral ?**

**Adjacent sides and Opposite sides**

**Consecutive Angles and opposite angles**

**Angle sum property of quadrilateral**

**The angle of a quadrilateral are respectively `100^@;98^@;92^@`. Find the fourth angle.**

**In a quadrilateral ABCD; the angles A;B;C and D are in ratio 1:2:3:4. Find the measure of each angles of the quadrilateral.**

**Trapezium and Parallelogram**

**Rhombus; Rectangle; Square and Kite**

**A diagonal of a parallelogram divides it into two congruent triangles.**

**In a parallelogram opposite sides are equal**