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A pentagon is such that one of its exterior angles is 60°. Two others are (90 - m°) each while the remaining angle are (30 + 2m) each. Find the value of m.​

User Clmarquart
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1 Answer

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Answer: m = 39

Explanation:

To find the value of m in the given pentagon, let's use the properties of exterior angles of polygons and the sum of interior angles of a pentagon.

1. The sum of the exterior angles of any polygon is always 360°.

2. The sum of the interior angles of a pentagon is always 540°.

Let's start by finding the measure of the three known angles:

- One exterior angle is given as 60°.

- Two other exterior angles are (90 - m)° each.

To find the remaining two exterior angles, we can subtract the sum of the known angles from 360°:

(90 - m)° + (90 - m)° + 60° = 360°

Simplifying the equation:

180° - 2m + 60° = 360°

Combining like terms:

240° - 2m = 360°

Next, let's find the interior angles of the pentagon:

The remaining interior angles are (30 + 2m)° each.

To find the sum of all interior angles, we multiply the number of sides (pentagon has 5 sides) by the measure of each interior angle:

5 * (30 + 2m)° = 540°

Simplifying the equation:

150° + 10m = 540°

Subtracting 150° from both sides:

10m = 390°

Finally, we can solve for m by dividing both sides of the equation by 10:

m = 390° / 10

m = 39°

Therefore, the value of m is 39°.

User Zaphoid
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