Find the value of x for the triangle 60 X 30

Olivia uses the work below to determine 55% of 720 which explains the error in olivia’s solution

The sixth grade art students are making a mosaic using tiles in the shape of right triangles.each tile has leg measures of 3 centimeters and 5 centimeters.i f there are 200 tiles in the mosaic what is the area of the mosaic.

Simplify (a/b - b/a) times (a - a^2/a+b) a - a^2/a=b is a mixed number