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
In a right triangle, the side opposite the right angle is called....?
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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