### Home > INT3 > Chapter 7 > Lesson 7.2.1 > Problem7-57

7-57.

Multiple Choice: Based on the relationships provided in the diagram, which of the equations below is correct? Justify your choice.

1. $4 x + 2 ^ { \circ } + 9 x - 3 ^ { \circ } = 90 ^ { \circ }$

1. $4 x + 2 ^ \circ = 9 x - 3 ^ { \circ }$

1. $4 x + 2 ^ { \circ } + 9 x - 3 ^ { \circ } = 180 ^ { \circ }$

1. $( 4 x + 2 ^ { \circ } ) ( 9 x - 3 ^ { \circ } ) = 90 ^ { \circ }$

This is an isosceles triangle because it has two congruent sides.
In an isosceles triangles base angles are equal.