Equilateral triangle with the side 4 cm and h=2.5 cm
In equilateral triangle all sides are equal
so all sides are equal in the base of the prism
lateral area of the prism = Perimeter of the base * height
Perimeter of the base equilateral triangle = side + side + side
lateral area of the prism =(side + side + side) * height
= (4+4+4) * 2.5
= 
lateral area of the prism = 
Given:
Irregular Shape:
Semi-circle and rectangle:
Area of a rectangle = l * w
Area of a semi-circle = (π r²)/2
Area of rectangle = 8 cm * 5 cm = 40cm²
Area of a semi-circle = (3.14 (4²))/2 = (3.14*16)/2 = 50.24/2 = 25.12cm²
4² is taken from diameter of 8cm divided by 2 to get the radius.
Total area = 40 cm² + 25.12 cm² = 65.12 cm²
Answer:
7 of the angles measure 144 degrees each and one angle measures 72 degrees
Step-by-step explanation:
Let
x -----> represent the measures of the seven same-size angles,
x/2 ----> represent the measure of the one that is "two times smaller."
we know that
The sum of internal angles of a polygon can be calculated as:

where
n is the number of sides of the polygon
In this case
n=8 (octagon)
substitute

so
The linear equation that represent this problem is

solve for x

so

therefore
7 of the angles measure 144 degrees each and one angle measures 72 degrees
Answer:
y=5-4x / 2
I cant do the fraction symbol