Question

In the following figure, find the 11. In the for value of y. А (2x+4) DK«x+10) (5y+5) B (4y-4) (1) 20" (2) 10° (3) 25° (4) 30°

11th - 12th Class

Maths

Solution

443

4.0 (1 ratings)

11. (3) since, ( A B C D ) is a cyclic quadrilateral. ( therefore ) ( angle A+angle C=180^{circ} ) ( Rightarrow 2 x+4+4 y-4=180^{circ} ) ( Rightarrow quad x+2 y=90^{circ} ) Also, ( angle B+angle D=180^{circ} ) ( Rightarrow 5 y+5+x+10=180^{circ} ) ( Rightarrow quad x+5 y=165^{circ} ) On subtracting Eq. (i) from Eq. (ii), we get ( 3 y=75^{circ} ) ( Rightarrow ) ( y=25^{circ} )