Answer:
405 of the students
Step-by-step explanation:
5,040 I think because 7•6•5•4•3•2•1=5040
First you need to divide 125 / 25 which is 5 then you do subtraction 21 x 5 which is 105, then you subtract again 125 - 105 which is 20, 20 light bulbs will be broken. Or you could have just multiplied 5 by 4 which is the amount of light bulbs that were broken which is a lot easier...
Angle ADB is a right angle, which is given.
The measure of ADB is 90 degrees by definition of right angle.
The two angles are a linear pair (aka they're supplementary) by definition of linear pair (they're formed by two intersecting lines).
The measure of BDC is 90 because BDC + ADB = 180 (definition of linear pair), and ADB = 90 (given).
BDC = ADB because 90 = 90
Overall, the two triangles are congruent by SAS.