SSC CGL 20201)Triangle PDC is drawn inside the square ABCD of side 24cm where P lies on AB. What is the area of the triangle ?
288\(cm^2\)
since ABCD is a square, Area of triangle PDC = \( {1 \over 2}\times CD \times PE\) = \( {1 \over 2}\times 24 \times 24 = 288 cm^2\)
SSC CGL 20202)In quadrilateral PQRS, \(RM\perp QS\), \(PN\perp QS\) and QS = 6 cm. If RM = 3 cm and PN = 2 cm, then the area of PQRS is
\(15cm^2\)
Area of quadrilateral PQRS = Area of \(\triangle PQS\) + Area of \(\triangle QRS\) =\({1\over2}\times QS\times PN + {1\over2}\times QS\times RM={1\over2}\times QS(PN + RM)={1\over2}\times6(2+3)=15 cm^2\)
3)In the figure. if \(\angle A = 100^0\) then \(\angle C = ?\)
SSC CGL 2020
\(80^0\)
ABCD is a cyclic quadrilateral. \(\angle A = 100^0\); \(\angle A + \angle C=180^0\); ⇒ \(\angle C = 180^0-100^0=80^0\)
SSC CGL 20204)The lengths of the diagonals of a rhombus are 16 cm and 12 cm. Its area is :
\(96\space cm^2\)
Area of rhombus = \(1\over2\) x first diagonal x second diagonal = \({1\over2}\times16\times12=96\space cm^2\)
SSC CGL 20205)ABCD is a cyclic quadrilateral which sides AD and BC are produced to meet at P, and sides DC and AB meet at Q when produced. If \(\angle A = 60^\circ\) \( and\space \angle ABC = 72^\circ,\)\( then\space \angle DPC - \angle BQC = ?\)
\(36^0\)
Since ABCD is a cyclic quadrilateral. \(\angle A+\angle C = 180 \) & \(\angle B +\angle D = 180^0\) ;
\(\therefore \angle C = 120^0\) & \(\angle D = 108^0\) ;
In \(\triangle PDC\) ⇒ \(\angle PDC = 180-108=72^0\) & \(\angle PCD = 180-120=60^0\) ;
\(\therefore \angle P = 180-72-60=48^0\) ;
Similarly, In \(\triangle BCQ\) ⇒ \(\angle Q = 12^0\) ; Now \(\angle P-\angle Q= 48^0-12^0=36^0\)
SSC CGL 20206)Sides AB and DC of cyclic quadrilateral ABCD are produced to meet at E, and sides AD and BC are produced to meet at F. If \(\angle ADC = 75^\circ\) and \(\angle BEC =52^\circ\), then the difference between \(\angle BAD\) and \(\angle AFB \) is:
\(31^0\)
ABCD is a cyclic quadrilateral. \(\angle ADC = 75^\circ\) ;
∴\(\angle ABC + ∠ADC=180^0\) ;
⇒ \(∠ABC = 180^0 − 75^0=105^0\) ;
⇒ \(∠CBE = 180^0 − 105^0=75^0\) ;
\(\therefore ∠BCE = 180-(52+75)=53^0\);
\(\angle BCD=180-53=127^0\) ;
\(\because \angle BCD+\angle BAD=180^0\) ; ⇒ \(\angle BAD = 53^0\);
\(\angle AFB = 180-(105+53)=22^0\) ;
Required difference = \(53^0-22^0=31^0\)