If 9 of the sparrows is 45% of the birds in the backyard, 9/x = 45/100.
Cross multiply to get 9 * 100 = 45x; simplified is 900 = 45x or 20.
This means that there are 20 birds in the backyard. You can check this by dividing 9/20 which equals 45%
Answer:
Step-by-step explanation:

Answer:
area= 1/2*(h*b) h- height, b- base
the triangle is isosceles (denoted by the 2 dashes on the sides of the triangle)
so they are equal in length
angles in triangle = 180
so 38+38=76
180-76=104
base=24
divide the triangle in the center
so now triangle 1(left) the base = 12
and triangle 2(right) the base = 12
use trigonometric ratios
in this we need to find the height
which is opposite of 38,
we already have the adjacent =12
so the ratio is Tan (Tangent Opposite/Adjacent)(TOA)
Tan38= (12/h)
multiply by h
h*Tan38=12
h=12/tan38 = 15.35929959