These 3 questions i need help

Find the domain of the following expression: 1/(√x)-2

20 points for the answer. this is for real , don't put random ! a rectangle has a length of 4 centimeters and a width of 7 centimeters. what is the effect on the perimeter when the dimensions are multiplied by 5? the perimeter is increased by a factor of 5. the perimeter is increased by a factor of 20. the perimeter is increased by a factor of 25. the perimeter is increased by a factor of 100.

Find the measure of angle b in the following triangle