#### Chapter 14 QuadrilateralsÂ R.D. Sharma Solutions for Class 9th Exercise 14.1

**Exercise 14.1**

1. Three angles of a quadrilateral are respectively equal to 110Â°, 50Â° and 40Â°. Find its fourth angles.

**SolutionÂ**

2. In a quadrilateral ABCD, the angles A, B, C and D are in the ratio 1 : 2 : 4 : 5. Find the measure of each angles of the quadrilateral.

**Solution**

**Solution**

4. The angles of quadrilateral are in ratio 3:5:9:13. Find all angles of the quadrilateral.Â

**Solution:**

We know that sum of all angles of a triangle is 360Â°

It is given; angles are in ratio 3:5:9:13. So, we can say, the angles are 3x, 5x, 9x and 13x.Â

Sum of all anglesÂ

3x+5x+9x+13x = 360Â°

â‡’30x=360Â°

â‡’x = 360Â°/30 = 12Â°

So, angles areÂ

3x = 3Ã—12Â°=36Â°

5x = 5Ã—12Â°=60Â°

9x =9Ã—12Â°= 108Â°

13x =13Ã—12Â°=156Â°

So, angles are 36Â°, 60Â°,108Â°, 156Â°