Let us recall parallelogram properties, which states that opposite angles of parallelogram are congruent.
We can see from graph that side US is parallel to TR and measure of angle U equals to measure of angle R, therefore, quadrilateral drawn in our given graph is a parallelogram.
Since we know that opposite sides of parallelogram are congruent. In our parallelogram UT=SR and US=TR.
In our triangle STU and triangle TSR side TS=TS by reflexive property of congruence.
Therefore, our triangles are congruent by SSS congruence.
25 + 100i is correct because -5 squared is 25 and the the square root of -100 is 100i or 10i in its simplest form.
i would say the answer is 17 because i used the calculator
Let's V the speed of the girl in step
v the speed of the escalator in step
L the length between ground and floor.
V*60+v*60=L ==> V+v=L/60
V*90-v*90=L ==> V-v=L/90
2V=L(3+2)/180
==>V=5L/360
Time to climb (in step) with v=0 (escalator standing still)
V*t=L==> t=L/V=L/(L*5/360)=72
The girl will count 72 steps.