## Algebra: A Combined Approach (4th Edition)

An isosceles triangle has two angles with the same measure. The measure of the third angle is 30$^{o}$ more than twice the measure of either of the other two. Let us call the third angle x and the two other angles y. $x=2y+30$ We also know that the sum of the angles of a triangle is 180$^{o}$. $x+2y=180$ $(2y+30) +2y=180$ $4y+30=180$ $4y=150$ $y=37.5$ Using the first equation, we can find out the other angle: $x=2(37.5)+30$ $x=105$