Q13 of 115 Page 8

Two unequal angles of a parallelogram are in the ratio 2 : 3. Find all its angles in degrees.

Let, ∠A = 2x and

∠B = 3x


Now,


∠AHB = 180o (Co. interior angles are supplementary)


2x + 3x = 180o


5x = 180o


x = 36o


∠A = 2x = 72o


∠B = 3x = 108o


Now,


∠A = ∠C = 72o(Opposite sides angles of a parallelogram are equal)


∠B = ∠D = 108o(Opposite sides angles of a parallelogram are equal)


More from this chapter

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11

In Fig 8.113, lines AB and CD are parallel and P is any point as shown in the figure. Show that ∠ABP +∠CDP = ∠DPB.

 12

In Fig 8.114, AB||CD and P is any point shown in the figure. Prove that:

∠ABP + ∠BPD + ∠CDP = 360°


 14

If each of the two lines is perpendicular to the same line, what kind of lines are they to each other?

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In Fig 8.115, ∠1=60° and ∠2= if a right angle. Prove that l||m.