Answer:
See explanation
Step-by-step explanation:
<u>Given:</u> ΔABC ≅ ΔDEF
AM, DN - medians
<u>Prove:</u> AM ≅ DN
Proof:
1. Congruent triangles ABC and DEF have congruent corresponding parts:
- AB ≅ DE;
- BC ≅ EF;
- ∠ABC ≅ ∠DEF.
2. BM ≅ MC - definition of the median AM;
3. EN ≅ NF - definition of the median DN;
4. AB ≅ 2BM, EF ≅ 2EN
BM ≅ 1/2 AB,
EN ≅ 1/2 EF,
thus, BM ≅ EN
5. Consider two triangles ABM and DEN. In these triangles \:
- AB ≅ DE (see 1));
- BM ≅ EN (see 4));
- ∠ABM ≅ ∠DEN (see 1).
So, ΔABM ≅ ΔDEN by SAS postulate.
6. Congruent triangles ABM and DEN have congruent corresponding sides BM and DN.
Answer: it is a rational
Step-by-step explanation:
Let speed of the boat in still water = x miles per hour
Let speed of the current = y miles per hour
When water and current both flow in same direction then effective speed will be sum of both speeds that is (x+y)
now plug the given values in formula speed=distance/time
we get equation:
(x+y)=160/8
or x+y=20...(i)
When water and current both flow in opposite direction then effective speed will be difference of both speeds that is (x-y)
now plug the given values in formula speed=distance/time
we get equation:
(x-y)=160/40
or x-y=4
or x=4+y...(ii)
plug value of x into (i)
4+y+y=20
4+2y=20
2y=16
y=8
plug value of y into (ii)
x=4+8=12
Hence final answer is given by:
Speed of the boat in still water = 12 miles per hour
Speed of the current = 8 miles per hour
There are 7 rows.
63/9 = 7.
Answer:
I am pretty sure it is the second option
Step-by-step explanation:
Hope this helps
