Triangle with all angles less than 90

There are three special names given to triangles that tell how many sides (or angles ) are equal. All angles are less than ° . A triangle is scalene if all of its three sides are different (in which case, the three angles are also different). The Scalene Triangle has no congruent sides.

Acute triangles have all acute angles.

The Obtuse Triangle has an obtuse angle (an obtuse angle has more than °).

To identify types of triangles based on the relationships of angles and sides.

Proof will show it works for all triangles. The angles happen to be 20°, 40° and 120°, and the sum of the angles is 20 . All three sides are not the same. But both of these equilateral triangles meet the constraint that at least two of the sides are equal. If you know the size of the angles you can!

Classifying Triangles according to the Size of their Angles. Example: Solve this triangle for the unknown internal angles : When no angles are known, the cosine rule is the only option. Step 1: Begin by using the cosine rule to find the largest angle. Less than ° - all three angles are acute and so the triangle is acute.

The title will change to reflect the type of triangle you have created. Right triangle : Has one degree angle. Isosceles triangle : Has two angles the same and two sides the same. Scalene triangle : Has all three angles and all three sides different.

Obtuse triangle : Has one obtuse angle , greater than degrees . Review ways to classify triangles based on their sides lengths and angles. An acute angle is any angle less than degrees. Practice classifying triangles.

This over here is less than degrees. So this is less than degrees. Learn how to draw acute, right, and obtuse angles with given points.

An obtuse triangle is one with one obtuse angle (greater than °) and two acute angles.