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mellib429
Jan 12, 2009, 07:11 PM
I have another quesiton.
This worksheet my teacher gave me says that a pentagonal beasball diamond has three right angles and the other two are congruent.
Well I know that the angle measures of a pentagon add up to 520
And that 3 90 degree angles equal 270.
Well when subtracting 270 from 520
I got 250 and then I divided that in half and got 125.
But that wasn't one of the answers.
Is this right or did I do something wrong?
The only answer close to the answer I got was 135.
The others were 54 67.5 and 90

mellib429
Jan 12, 2009, 07:14 PM
Never mind.
The angle measures of a pentagon equal 540.

Credendovidis
Jan 14, 2009, 06:42 PM
The angle measures of a pentagon equal 540.
Good : a little thinking often solves the problem !
You'll never forget that 540 degrees now !

Remember :

Internal angles of a regular :

3 - Triangle = 60 deg - total = 180 deg
4 - Square = 90 deg - total = 360 deg
5 - Pentagon = 108 deg - total = 540 deg
6 - Hexagon = 120 deg - total = 720 deg
7 - (H)Septagon = 128.57 deg - total = 900 deg
8 - Octagon = 135 deg - total = 1080 deg
9 - Nonagon = 140 deg - total = 1260 deg
10-Decagon = 144 deg - total = 1440 deg

:)


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