8.235 times 10^-4 in standard form

Acity plans to build a new rectangular-shaped park. the perimeter of the park will be 940 meters. the width of the park will be 300 meters. what will be the length, in meters, of the new park?

Given: circle o, cd is diameter, chord ab || cd. arc ab = 74°, find arc ca.

Given the expression (7 ? 4i) ? (2 + 6i), perform the indicated operation and write the answer in the form a + bi.