If vertex angle is 42, and the base angles are congruent, this is an isosceles triangle, they each measure: 180-42/2. They each measure 69 degrees. The length of sides don't matter.
23
because
the pattern is
(5 10) ..1.. (15 20) ..2.. (25 30) ..3..
..1... = 3
..2.. = 13
so ..3.. = 23
Graphing by hand isn’t always accurate and can be stressful when using a graphing calculator it gives you the correct answers and is more reliable
This is the formula you would use to calculate how many tiles you would need.
# of tiles you need = Total square footage ÷ square footage of each tile
Total square footage: 69x69 = 4761 square feet
Square footage of each tile = 2x2 = 4 square feet
# of tiles you need = 4761 ÷ 4 = 1190.25
You will need 1190.25 tiles.