Identify which type of triangle appears in the drawing:
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Identify which type of triangle appears in the drawing:
Note that the sum of angles in a triangle equals 180 degrees.
Let's calculate X in the following way:
Let's divide both sides by 9:
Now let's calculate the angles:
This means that in the triangle we have 3 angles: 20, 60, 100
Given that we have one angle that is greater than 90 degrees, meaning an obtuse angle, this is an obtuse triangle.
Obtuse triangle
Look at the angles shown in the figure below.
What is their relationship?
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A triangle is obtuse if any one angle is greater than 90°. In this problem, since 5x = 100° > 90°, it's an obtuse triangle. Only one angle needs to be obtuse!
The variables alone don't tell you the actual angle measures! You must solve for x first, then calculate each angle. The same variables could give different triangle types depending on the value of x.
Check your algebra! Since angles in a triangle are always positive, x must be positive. If you get negative values, you likely made an error in setting up or solving the equation .
No, impossible! If two angles were each greater than 90°, their sum alone would exceed 180°. Since all three angles must sum to exactly 180°, only one angle can be obtuse.
Just check the largest angle to classify the triangle!
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