Answer:
The correct option is C ) 109.5°
Therefore,

Step-by-step explanation:
Given:
In Triangle DEF
d = 10
e = 18
f = 12
To Find
angle E = ?
Solution:
In Triangle DEF , Cosine Rule says

Substituting the values we get


Therefore,

............As it is in Second Quadrant
Therefore,

Ratio of areas of similar triangles is 9 : 25.
Solution:
Given data:
Ratio of sides of two similar triangles = 3 : 5
To find the ratio of areas of the triangles:
We know that,
<em>In two triangles are similar, then the ratio of their area is equal to the square of the ratio of their sides.</em>



Ratio of areas of similar triangles is 9 : 25.
Answer:
B) 6, 8, 10
Step-by-step explanation:
All right triangles will follow the following theorem (Pythagorean theorem):
, where
and
are two legs of the triangle and
is the hypotenuse. Out of all answer choices, only B) 6, 8, 10 follow this theorem.
Answer:
+35 per month
Step-by-step explanation: