Parallelogram's angles are in the ratio of 5:15:9:7.

What is the difference between largest and least angle of parallelogram?

1 answer

In a parallelogram, opposite angles are equal and the sum of the angles is \(360^\circ\). Given that the angles are in the ratio of \(5:15:9:7\), we can represent the angles as:

  • \(5x\)
  • \(15x\)
  • \(9x\)
  • \(7x\)

Since opposite angles are equal, we can equate pairs of angles:

  1. \(5x\) and \(15x\)
  2. \(9x\) and \(7x\)

However, this representation is incorrect because we should consider that all four angles should only sum to \(360^\circ\). Thus, we can find the total ratio parts:

\[ 5 + 15 + 9 + 7 = 36 \]

Let each angle be \(kx\), where \(k = 36\) and \(x\) is a common multiplier.

Then we can represent the angles as:

  • \(5k = 5x\)
  • \(15k = 15x\)
  • \(9k = 9x\)
  • \(7k = 7x\)

Setting the ratio to sum up to \(360^\circ\):

\[ (5 + 15 + 9 + 7)x = 360 \]

Calculating this gives:

\[ 36x = 360 \]

Solving for \(x\):

\[ x = \frac{360}{36} = 10 \]

Now, we can find each angle:

  • \(5x = 5 \cdot 10 = 50^\circ\)
  • \(15x = 15 \cdot 10 = 150^\circ\)
  • \(9x = 9 \cdot 10 = 90^\circ\)
  • \(7x = 7 \cdot 10 = 70^\circ\)

The angles of the parallelogram are \(50^\circ\), \(150^\circ\), \(90^\circ\), and \(70^\circ\).

Now we need to identify the largest and smallest angles:

  • Largest angle: \(150^\circ\)
  • Smallest angle: \(50^\circ\)

Finally, the difference between the largest and smallest angle:

\[ 150^\circ - 50^\circ = 100^\circ \]

Thus, the difference between the largest and least angle of the parallelogram is \(100^\circ\).