Both figures always have four sides
Answer:
t=-58
Step-by-step explanation:

Answer:
<h2>a = 400/21, b = 580/21</h2>
Step-by-step explanation:
Small triangles are similar. Therefore, the sides are proportional
<em>cross multiply</em>
<em>divide both sides by 21</em>

For b, we can use the Pythagorean theorem:

Use the formula i=prt, where i is the interest earned, p is the principal, r is the rate (as a decimal fraction) and t is the elapsed time, in years.
Here i = $72 = $1200 r (9/12) (9 months is 9/12, or 3/4, of 1 year)
Reducing,
$72 = $900r
Solving for r, r=0.08, or 8 percent per year.