Area = perimeter + 132.
Let each side of the city be x miles long, then:-
x^2 = 4x + 132
x^2 - 4x - 132 = 0
x = [-(-4) +/- sqrt((-4)^2 - 4 * 1 *-132)] / 2
x = 13.66, -9.66 We ignore the negative
So the city has dimension of 13.66 * 13.66
13.7 * 13.7 to nearest 10th
Given : tan 235 = 2 tan 20 + tan 215
To Find : prove that
Solution:
tan 235 = 2 tan 20 + tan 215
Tan x = Tan (180 + x)
tan 235 = tan ( 180 + 55) = tan55
tan 215 = tan (180 + 35) = tan 35
=> tan 55 = 2tan 20 + tan 35
55 = 20 + 35
=> 20 = 55 - 35
taking Tan both sides
=> Tan 20 = Tan ( 55 - 35)
=> Tan 20 = (Tan55 - Tan35) /(1 + Tan55 . Tan35)
Tan35 = Cot55 = 1/tan55 => Tan55 . Tan35 =1
=> Tan 20 = (Tan 55 - Tan 35) /(1 + 1)
=> Tan 20 = (Tan 55 - Tan 35) /2
=> 2 Tan 20 = Tan 55 - Tan 35
=> 2 Tan 20 + Tan 35 = Tan 55
=> tan 55 = 2tan 20 + tan 35
=> tan 235 = 2tan 20 + tan 215
QED
Hence Proved
Definition: Triangles are congruent when they have exactly the same three sides and exactly the same three angles.
From the diagram you have that:
Triangles QRS and TUV have congruent corresponding sides and congruent corresponding angles. This means they are congruent triangles. Congruent triangles always have the same shape and the same size. Also each pair of congruent triangles is a pair of similar triangles with ratio of similarity equal to 1.
Answer: all choices are correct.
Round 8.1 down to 8
Round 4.2 down to 4
8(4)= 32
The estimated product is 32.
Hope this helps!
