Solve for X: Triangle with 115° Angle and Expressions 8X and 20+X

Question

Calculate the value of X.

11511511520+X20+X20+XAAABBBCCC8X

Video Solution

Solution Steps

00:00 Find X
00:03 The sum of angles in a triangle equals 180
00:07 Substitute appropriate values according to the given data and solve for X
00:14 Collect like terms
00:18 Isolate X
00:28 And this is the solution to the problem

Step-by-Step Solution

Let's remember that the sum of angles in a triangle is equal to 180.

Therefore, we will use the following formula:

A+B+C=180 A+B+C=180

We'll substitute the known data:

115+8x+20+x=180 115+8x+20+x=180

We'll combine similar terms:

9x+135=180 9x+135=180

We'll move terms to one side and maintain the appropriate sign:

9x=180135 9x=180-135

9x=45 9x=45

We'll divide both sides by 9:

x=5 x=5

Answer

5