You can calculate it using the law of cosines: c^2=a^2+b^2-2*a*b*cos(C)
your triangle is
CD=15=a
CE=?=b
DE=CE+3=b+3=c
and C=90°
-> insert those values, with c substituted with b+3 to remove c
c^2=a^2+b^2-2*a*b*cos(C)
(b+3)^2=15^2+b^2-2*15*b*cos(90)
cos(90)=0->
(b+3)^2=15^2+b^2
b^2+2*3*b+3^2=225+b^2
6b+9=225
6b=216
b=36=CE
DE=CE+3=36+3=39
There is nothing wrong with Arlene's math. Her answer is correct. The mistake is that she has cited the "associative property" where the "commutative property" should have been cited, and vice versa.
The associative property has to do with where you put parentheses. The commutative property has to do with what order the operands are in.
Answer:
14π cm
Step-by-step explanation:
arc length = rΘ
arc length= 63(2π/9)
arc length= 14π cm
Hope this helps!
Please mark brainliest if you think I helped! Would really appreciate!
