a boy is building a pyramid out of building blocks. he put 20 blocks in the first row, then he puts 19 blocks in the row above, and so on. find the total number of blocks he needs. find the total number of blocks he need

answer: a

step-by-step explanation: the answer is a due to the rule of symmetry; that a line of symmetry must divide a figure into 2 pieces that are the exact same, only reflected over a line of symmetry. b and c do not have lines of symmetry and would not divide the figure evenly, thus making the answer a.

85.3-64 = 21.3

so laura has already added 85.3 grams of chocolate powder and she has gone over the amount specified in the recipe by 21.3 grams

hope i ! have a great  day!

show us the triangle so we can answer it

d will be the best answer