Home

Algebra and Pre-Algebra Lessons

Algebra 1 | Pre-Algebra | Practice Tests | Algebra Readiness Test

Algebra E-Course and Homework Information

Algebra E-course Info | Log In to Algebra E-course | Homework Calculator

Formulas and Cheat Sheets

Formulas | Algebra Cheat Sheets

Writing and Solving Equations

by Chuck

Find the measure of the largest angle of a triangle if it's 3 times as large as the smallest angle and the second angle is 20 degrees larger than the smallest angle. (The sum of the measures of the angles of a triangle is 180 degrees.)

Comments for Writing and Solving Equations

Average Rating     Dec 09, 2010 Rating     Writing and Solving Equations by: Karin Since all of the information is centered around the smallest angle, we are going to assign this as our variable. Let the smallest angle = x (degrees) The second angle is 20 degrees larger so this means: x + 20 The largest angle is 3 times as large as the smallest angle, so this means: 3x Now we can add our three angles together and they must equal a total of 180 degrees. x + (x+ 20) + 3x = 180 Step 1: Combine like terms x + x + 3x + 20 = 180 5x + 20 = 180 Step 2: Subtract 20 from both sides. 5x + 20 -20 = 180 - 20 5x = 160 Step 3: Divide by 5 on both sides. 5x/5 = 160/5 x = 32 degrees. If x is 32 degrees this means that the smallest angle is 32 degrees. The 2nd angle is 32 + 20 = 52 degrees. The largest angle is 3(32) = 96 degrees. Check your answers: 32+52+96 = 180 I hope this helps, Karin

Top of the Page

Custom Search