Open Middle®
Directions: Using the digits 1 to 9 at most one time each, place a digit in each box to make a triangle with side lengths that give the corresponding area.
Hint
How do you calculate the area of a triangle?
Answer
Multiple Answers. A base of 3, a height of 8, and an area of 12. A base of 4, a height 9, and an area of 18. A base of 6, a height of 9 and an area of 27. A base of 8, a height of 9, and an area of 36.
Source: Owen Kaplinsky
12×39=487
2×7=14
What is the corresponding area?
All 8 possible answers:
height 3, base 8, area 12
height 4, base 6, area 12
height 4, base 8, area 16
height 4, base 9, area 18
height 6, base 7, area 21
height 6, base 8, area 24
height 6, base 9, area 27
height 8, base 9, area 36
Plus of course 8 more triangles where you simply swap height and base.
7 x 2 = 14
A base of 3, a height of 8, and an area of 12. A base of 4, a height 9, and an area of 18. A base of 6, a height of 9 and an area of 27. A base of 8, a height of 9, and an area of 36.
if you have a even number there divide it by half