No.4- This is not a triangle since one side should be less than the sum of the 2 other sides. In this case 8=3+5, hence it's equal & not smaller
N0.5- This is an isosceles triangle & there are an infinity of triangles with the mentioned degrees. (these are called similar triangle)
No6- This is a unique triangle
No.7- If the plane is parallel to the bases, then the slicing is a cercle.
But if the plane (Parallelogram) is tilt, then the slicing is an ellipse
Answer:

Step-by-step explanation:
Given
See attachment for triangle
Required
Find x
To do this, we simply apply sin formula which is:

In this case, it is:


Take arcsin of both sides


--- approximated
Answer:
1. x^3+27y^3
2. 10a^3+17a^2b+11ab^2+12b^3
Step-by-step explanation:
Answer: The answer is (b) [(p∧q)⇒r] ∧ [r⇒(p∧q)].
Step-by-step explanation: Given that The statements 'p', 'q' and 'r' are defined as follows.
p : it is cold,
q : it is humid,
r : it is snowing.
The statement 'it is cold and humid if and only if it is snowing' can be written as
(p∧q) ⇔ r.
We know that r ⇔ s can be written as (r⇒s)∧(s⇒r).
So, (p∧q) ⇔ r can be written as [(p∧q)⇒r] ∧ [r⇒(p∧q)].
Thus, the answer is (b) [(p∧q)⇒r] ∧ [r⇒(p∧q)].