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for a 90 you have to use Pythagoras rule a2+b2=c2 c been the longest side usually in front of the right angle side. For a 30 you have to use this formula 1/2absinc. ab are the two sides you know and c is the angle 30. The same thing works for 60 degree triangle also. hope i helped.

Q: How do you find missing sides of a 30-60-90 triangle?

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The way to find the missing side of a triangle-THIS ONLY WORKS ON RIGHT ANGLED TRIANGLES-is square both sides seperately and then add them together to give you the square of the missing side-find the square root and that is the size of the missing side-eg. if you have a RIGHT ANGLED TRIANGLE with sides of 3inch and 4inch then (3x3) + (4x4) = 25 so the square root of 25 is 5 meaning the missing side is 5inch.

180-x-y (x and y are the sides you already know) there are 180 degrees in a triangle. The remaining # is the last angle

That really depends what else you know about the triangle. For example, if you only know the lengths of two sides, you simply don't have enough information.

It depends on what information you do have. There are different solutions depending on whether you have two sides and the included angle, or two sides and a median, two sides and an altitude, etc.

you must know more information. Like the lengths of 2 sides. Then using Trig (law of sines or law of cosines) you can find the remaining sides and angles.

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The way to find the missing side of a triangle-THIS ONLY WORKS ON RIGHT ANGLED TRIANGLES-is square both sides seperately and then add them together to give you the square of the missing side-find the square root and that is the size of the missing side-eg. if you have a RIGHT ANGLED TRIANGLE with sides of 3inch and 4inch then (3x3) + (4x4) = 25 so the square root of 25 is 5 meaning the missing side is 5inch.

A triangle always has 180 units. You would have to add up the two sides and subtract that from 180.

180-x-y (x and y are the sides you already know) there are 180 degrees in a triangle. The remaining # is the last angle

To create a triangle, the sum of the two shorter sides must be greater than the third side. If the longest side is one of the two given sides, then the missing side must be greater than the difference between the two shorter sides. If the missing side is the longest side then the missing side must be less than the sum of the two shorter sides.

a triangle always has three sides

That really depends what else you know about the triangle. For example, if you only know the lengths of two sides, you simply don't have enough information.

to find the missing side of a right triangle you need the pythagorean theorem. A2 + B2 = C2. c is the longest side and a and b is the other sides. no particular side is a or b just the longest side is c.

You use the Pythagoras Theorem if it is a right-angled triangle. a squared + b squared = h (longest side, diagonal) squared, then square root h to find the longest side. if it is not a right angled triangle, then use the Sine or Cosine rule. Sine rule for: two angles and any one side or two sides and an angle that is not in between the sides. Cosine rule for: all three sides (but then you do not need to find a missing side) or two sides and an angle that is in between.

It depends on what information you do have. There are different solutions depending on whether you have two sides and the included angle, or two sides and a median, two sides and an altitude, etc.

you must know more information. Like the lengths of 2 sides. Then using Trig (law of sines or law of cosines) you can find the remaining sides and angles.

Use two sides and Pythagoras's theorem to work out the third side. Then simply add the three sides.