# Understanding Acute Triangles in Geometry

## What is a Triangle in Geometry?

In geometry, a triangle is a closed figure made of three connected lines and three angles. All three angles of a triangle must add up to 180 degrees. The three angles of a triangle are referred to as triangle angles. The triangle angles can be acute, obtuse, or right angles. An acute angle is an angle that is less than 90 degrees. An obtuse angle is an angle that is greater than 90 degrees. A right angle is an angle that is exactly 90 degrees.

## What is an Acute Triangle?

An acute triangle is a triangle with three acute angles. All three triangle angles must be less than 90 degrees for a triangle to be considered an acute triangle. An acute triangle does not have any obtuse angles or right angles. The three triangle angles can all be equal, meaning the triangle is an equilateral triangle, or two angles can be equal, meaning the triangle is an isosceles triangle.

## Geometry Triangle Properties

An acute triangle has several properties that must be taken into consideration when studying geometry. One of the most important properties of an acute triangle is that the sum of the three triangle angles must be 180 degrees. Another property is that the longest side of the triangle must be shorter than the sum of the other two sides. This property is known as the triangle inequality theorem.

## Isosceles Triangle

An isosceles triangle is a type of acute triangle in which two of the triangle angles are equal. This means that two sides of the triangle are also equal in length. An isosceles triangle has two equal sides and two equal angles, and the third side is the longest side of the triangle. An isosceles triangle also has two additional properties; the altitude of the triangle must be perpendicular to the base, and the base angles must be equal.

## Right Triangle

A right triangle is a type of acute triangle in which one of the triangle angles is a right angle. A right angle is an angle that is exactly 90 degrees. In a right triangle, the longest side of the triangle is the side opposite the 90-degree angle, and this side is also referred to as the hypotenuse. The other two sides of the triangle are referred to as the legs. The legs of a right triangle must be perpendicular to each other.

## Practice Problems

Answer the following questions to test your understanding of acute triangles in geometry:

- What type of triangle angle is less than 90 degrees?
- What is the sum of all three triangle angles in an acute triangle?
- What type of triangle has two equal sides and two equal angles?
- What is the longest side of a right triangle called?
- In an isosceles triangle, what must the altitude be perpendicular to?
- What type of triangle has one right angle?

Answers: 1. Acute angle; 2. 180 degrees; 3. Isosceles triangle; 4. Hypotenuse; 5. Base; 6. Right triangle.

## Summary

In this article, we explored acute triangles in geometry. We discussed what a triangle is, what an acute triangle is, and the properties of acute triangles. We also discussed isosceles triangles and right triangles, and practiced our knowledge with a set of practice problems. Acute triangles are important to understand when studying geometry, as they are a fundamental part of geometry.

## FAQ

### What is acute triangle and its properties?

An acute triangle is a triangle whose angles are all less than 90°. This means that all the sides of an acute triangle are of different lengths, and the longest side is opposite the largest angle. The properties of an acute triangle include the fact that the sum of the angles is 180°, and the sum of the lengths of any two sides is greater than the length of the third side.

### What is acute angle explain with example?

An acute angle is an angle that is less than 90°. An example of an acute angle would be an angle that measures 45°. This angle is less than 90°, so it is considered an acute angle.

### What are three acute triangles?

Three acute triangles are triangles with angles that measure less than 90°. Examples of acute triangles include a triangle with angles measuring 30°, 60°, and 90°; a triangle with angles measuring 45°, 45°, and 90°; and a triangle with angles measuring 60°, 60°, and 60°.