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Find the four angles of a cyclic quadrilateral ABCD in which ZA = 2x – 1°, ZB = y + 5°,ZC = 2y + 15º and ZD = 4x - 7º.1 |
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Answer» Answer We KNOW that the sum of the opposite angles of a cyclic QUADRILATERAL is 180 o . In the cyclic quadrilateral ABCD, angles A and C and the angle B and D form pairs of opposite angles. ∴∠A+∠C=180 o and ∠B+∠D=180 o
⇒2x−1+2y+15=180 and y+5+4x−7=180 ⇒2x+2y=166 and 4x+y=182 ⇒x+y=83 ..(i) and, 4x+y=182 ..(ii) Subtracting equation (i) from equation (ii), we get 3x=99⇒x=33 Substituting x=33 in equation (i), we get y=50 Hence, ∠A=(2×33−1) o =65 o ,∠B=(y+5) o =(50+5) o =55 o
∠C=(2y+15) o =(2×50+15) o =115 o and ∠D=(4×33−7) o =125 o . PLEASE mark me as branlist |
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