What must Sara get on her next test to average 80% if her previous test scores were 78, 88, 83, and 81?
1 answer:
You might be interested in
Answer:
AD = 15 cm , BD = 3 cm
Step-by-step explanation:
Δ ABC is similar to Δ ADE ( by the AA postulate )
then the ratios of corresponding sides are in proportion, that is
=
( substitute values )
=
( cross- multiply )
8 × AD = 12 × 10 = 120 ( divide both sides by 8 )
AD = 15 cm
AB + BD = AD , that is
12 + BD = 15 ( subtract 12 from both sides )
BD = 3 cm
Check the picture below.
so the picture has a rectangle that is 8 units high and 12 units wide, and it has a couple of "empty" trapezoids, with a height of 5 and "bases" of 9 and 3.
now, if we just take the whole area of the rectangle and then subtract the area of those two trapezoids, what's leftover is the blue area.
