10+15+20+25+30+35+40+45+50+55+60+65=450
There are 450 seats in the auditorium
*pst* Put as most brainliest
12. the change in temperature is -1 C. -3 C + -1 C= -4 C
13. The net gain. Lin gained 14 yards, then loss 7 yards, and lastly gained 9 yards
14 + (-7) + 9= 16 yards
14. Pythagoras was born 582 BC. Newton 1643 AD
1643-582= 1,061 years
15. Sonny has $75 but he needs to buy something costs $93
he needs to borrow $18.
93-75= $18
Answer to the question
-20
1. Place your compass point on X and measure the distance to point Y. Swing an arc of this size above (or below) the segment.
2. Without changing the span on the compass, place the compass point on Y and swing the same arc, intersecting with the first arc.
3. Label the point of intersection as the third vertex of the equilateral triangle.
4. Use you straight edge and connect the points.