Step-by-step explanation:
We are going to start by working out the interior angles so first of all to work out the interior angle we used the formula: num of sides - 2 * 180 for the sum of degrees in a shape.
Lets test this formula.
Lets say we have a square it has 4 sides 4-2 = 2 *180 = 360 this is correct,meaning we can trust this formula.
Now lets put it to use.
Octagon has 8 sides - 2 = 6.
6 * 180 = 1080
Pentagon has 5 sides - 2 = 3
3 * 180 = 540
Another Pentagon 5 sides - 2 = 3
3 * 180 = 540
We have to find out a single angle because it is one side that joins to the other, also if it is a perfect fit then all the single angles must add up to 360.
1080/8 sides = 135 degrees
540 / 5 sides = 108 degrees
540 / 5 sides = 108 degrees
We add these up,
135 + 108 + 108 = 351 which cannot be a possible fit because we need 360 degrees.
Hope this helps
Answer:
A) 42 is the correct answer, I just did .84 times 50 and that equals 42.
Step-by-step explanation:
Answer:
about 77 cm^2
Step-by-step explanation:
From 3 sides, the area of a triangle is conveniently calculated using Heron's formula:
A = √(s(s -a)(s -b)(s -c))
where s is the semi-perimeter: s = (a+b+c)/2.
For the given values of a, b, c, we have ...
s = (a+b+c)/2 = (18 +11 +14)/2 = 21.5
A = √(21.5·3.5·10.5·7.5) = √5925.9375
A ≈ 76.9801 . . . cm^2
The area is about 77 square centimeters.
Count the units on the sides. On the Y axis the rectangle is 4 units and on the X axis the rectangle is 6 units. Area of a rectangle=L*W so, 6*4=24. Perimeter is 4*2 and 6*2=8+12=20. Hope this helps!
