If I really understood the question, they ask the area of the small rectangle 3.5x2 . If so it's 7mm²
Exterior Angles Theorem is used.
The exterior angle of a triangle is equal to the 2 opposite interior angles.
Therefore, 65+78=143°, since 65 and 78 are the 2 opposite interior angles.
So, the answer is 143°
'' In math, a geometric series is a series with a constant ratio between successive terms.
Answer:
The height of the equilateral triangle is 
Step-by-step explanation:
we know that
An equilateral triangle has three congruent sides, and three congruent angles that each measure 60 degrees
To find out the height of an equilateral triangle, apply the Pythagoras Theorem in the right triangle ABD
Remember that the height of an equilateral triangle bisects the base.
see the attached figure to better understand the problem

substitute the given values

Solve for BD




simplify
`
therefore
The height of the equilateral triangle is 
Answer:1/6
Step-by-step explanation:
15+3 =18
= 1/6