Regular triangle

[tex]\[
\begin{aligned}
\text{Angles} & =(n-2)\left(180^{\circ}\right) \\
& =(3-2)\left(180^{\circ}\right) \\
& =180^{\circ}
\end{aligned}
\][/tex]

[tex]\[
\begin{array}{l}
\frac{180^{\circ}}{n}=\frac{180^{\circ}}{3}=60^{\circ} \\
\end{array}
\][/tex]

Each side = 5 cm

Each angle = 60^{\circ}



Answer :

Certainly! Let's thoroughly break down the problem and solution step-by-step:

### Step 1: Determine the Number of Sides

Since we are dealing with a triangle, the number of sides [tex]\( n \)[/tex] is:
[tex]\[ n = 3 \][/tex]

### Step 2: Calculate Each Interior Angle

For a regular polygon with [tex]\( n \)[/tex] sides, the formula for each interior angle is:
[tex]\[ \text{Each interior angle} = \frac{(n - 2) \times 180^\circ}{n} \][/tex]

Plugging in [tex]\( n = 3 \)[/tex]:
[tex]\[ \text{Each interior angle} = \frac{(3 - 2) \times 180^\circ}{3} \][/tex]
[tex]\[ \text{Each interior angle} = \frac{1 \times 180^\circ}{3} \][/tex]
[tex]\[ \text{Each interior angle} = 60^\circ \][/tex]

Thus, each interior angle of a triangle is [tex]\( 60^\circ \)[/tex].

### Step 3: Simplify the Calculation for Verification

To verify, we can use a simpler check by dividing 180 degrees by the number of sides [tex]\( n \)[/tex]. For regular polygons, the exterior angle is given by:
[tex]\[ \text{Exterior angle} = \frac{360^\circ}{n} \][/tex]

Since interior and exterior angles are supplementary:
[tex]\[ \text{Interior angle} = 180^\circ - \text{Exterior angle} \][/tex]
[tex]\[ \text{Interior angle} = 180^\circ - \frac{360^\circ}{3} \][/tex]
[tex]\[ \text{Interior angle} = 180^\circ - 120^\circ \][/tex]
[tex]\[ \text{Interior angle} = 60^\circ \][/tex]

### Step 4: Side Length and Example Angles

Given:
- Each side of the triangle is 5 cm.
- An example angle provided is [tex]\( 10^\circ \)[/tex].

### Summary of Results

The resulting calculations for interior angles of a regular triangle confirm that:
[tex]\[ \text{Each interior angle} = 60^\circ \][/tex]
and simplified check assures us:
[tex]\[ \text{Interior angle per side} = 60^\circ \][/tex]

Therefore, our final detailed solution shows that for a regular triangle (equilateral triangle):
[tex]\[ \text{Each interior angle} = 60^\circ \][/tex]