Answer:
The 21st term is 137.
Step-by-step explanation:
Arithmetic progression:
In an arithmetic progression the difference between consecutive terms is always the same, and its called common difference.
The nth term is given by:
In which is the first term and d is the common difference.
The first two terms are -3, 4.
This means that
So
The 21st term is
The 21st term is 137.
Answer:
(1) D.Angle C is congruent to to Angle F. (2) C. SSS. (3) C. cannot be congruent to.
Step-by-step explanation:
1)
From the given figure it is noticed that
According to SAS postulate, if two sides and the included angle of one triangle are congruent to two sides and the included angle of another triangle, then both triangles are congruent.
The included angles of congruent sides are angle C and angle G.
So, condition "Angle C is congruent to to Angle F" will prove that the ∆ABC and ∆EFG are congruent by the SAS criterion.
2)
If
According to SSS postulate, if all three sides in one triangle are congruent to the corresponding sides in the other.
Since two corresponding sides are congruent but third sides of triangles are not congruent, therefore SSS criterion for congruence is violated.
3)
Since two corresponding sides are congruent but third sides of triangles are not congruent, therefore the included angle of congruent sides are different.
Therefore angle C and angle F cannot be congruent to each other.
