4621 rounded off to one significant figure​

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.

Find the magnitude, correct to two decimal places, made by each of the following with positive direction of the x axis a) y= x the answer is 45° but i don’t know how

What is the best approximation for the area of a circle with a radius of 4 m ? use 3.14 to approximate pi