If a triangle has sides of 7 cm and it is an equilateral you can draw a line right down the middle to form two congruent triangles.
These smaller triangles have a hypotenuse of 7cm and a base of 3.5 cm (7/2)
To work out the height, use Pythagoras’ theorem.
a^2 + b^2 = c^2 where c is the hypotenuse and a and b are the other two sides
7^2 - 3.5^2 = 36.75
Square root answer
= 6.06 cm
That’s the height of the triangle
Area of a triangle is base x height divided by 2
So 7 x 6.06 = 42.43…
/2
= 21.2 cm^2 to one d.p
Hope this helped!
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Answer:
C. 1/5
Step-by-step explanation:
Original * scale factor = Scaled
25 * SF = 5
Divide each side by 25
25/25 * SF = 5/25
SF = 1/5
Answer:

Step-by-step explanation:
The formula for the area of a circle is
, r is your radius, A is your area, and π is pi (3.1415...). You plug in your radius, or 5 into r, square it, 25, and multiply it by pi. You may be asked to use a certain number of digits of pi, and in that case you multiply for example 3.14 by 25, however
is the exact answer.
Answer:
B is the right answer
Step-by-step explanation:
because of negative 7 on the right it shows that it is down 7
Total area: pi*9^2 = 81pi
Shaded area = Total area / 3, because 120/360 = 1/3
So Shaded area = 81pi/3 = 27pi