How do scientists know that dark matter exists? A) It’s heat raises the temperature of space.

B) Its gravity affects objects around it.

C) It gives off electromagnetic waves.

D) All of these.

Rectangle qrst is shown. angle qrt is congruent to angle str, and angle str is complementary to angle qtr. which statement is true about angles qrt and qtr? they are congruent. they are complementary. they are supplementary. they are right angle