Exercise 12 Page 132

The sum of the measures of the interior angles of a triangle is 180^(∘).

50^(∘), 55^(∘), and 75^(∘)

Practice makes perfect

We want to find the measures of the angles in the given triangle.

To find these angle measures, we will first recall a key piece of information!

Angle Sum of a Triangle
The sum of the measures of the interior angles of a triangle is 180^(∘).

With this rule, we can write an equation connecting the measures of the angles of our triangle. x^(∘)+ 55^(∘)+ 50^(∘)=180^(∘) Let's solve the equation and find the value of x. For simplicity, we will not write the degree symbol.

x+55+50=180

AddTerms

Add terms

x+105=180

SubEqn

LHS-105=RHS-105

x=75

The measures of the interior angles of the triangle are 50^(∘), 55^(∘), and 75^(∘).

Subchapter links

1 Parallel Lines and Transversals p.131

2 Angles of Triangles p.132

3 Angles of Polygons p.132-133

4 Using Similar Triangles p.133

Exercise 12 Page 132

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