Answer:
Q7. 11.3 inches (3 s.f.)
Q8. 96.2 ft
Q9. 36.4cm
Step-by-step explanation:
Q7. Please see attached picture for full solution.
Q8. Let the length of a side of the square be x ft.
Applying Pythagoras' Theorem,

Thus, the perimeter of the square is

Q9. Equilateral triangles have 3 equal sides and each interior angle is 60°.
Since the perimeter of the equilateral triangle is 126cm,
length of each side= 126÷3 = 42 cm
The green line drawn in picture 3 is the altitude of the triangle.
Let the altitude of the triangle be x cm.
sin 60°= 
(to 3 s.f.)
Therefore, the length of the altitude of the triangle is 36.4cm.
Answer is 10 and 170, complementary angles are 90°, while supplementary angles are 180 in total, if angle A is 80 then you subtract 90 by 80 and you get 10, so that is angle B, So then you are asked what is angle C. Which is part of the supplementary angle so you take the 10° that you got from B and then you subtract 180 by the 10, And thats how you get 170 and that's how you know that C is 170 (hope this explanation helps)
Step-by-step explanation:
y-y1 = m(x-x1) is the equation for a linear line in y=mx+b (slope intercept)
slope = m = -5/8
x1 = -14
y1 = 6
y-6 = -5/8 (x--14)
y-6 = -5/8 (x+14)
y-6 = -5/8x-70/8
y-48/8= -5/8x-70/8
y = -5/8x - 22/8
When x = 0, y = -22/8, which makes (0, -22/8) your y intercept
Answer:
The answer is

Step-by-step explanation:
To find an equation of a line given the slope and a point we use the formula

where
m is the slope
( x1 , y1) is the point
From the question the point is (2, 4) and the slope is 3
The equation of the line is

We have the final answer as

Hope this helps you
Answers:
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How to get those answers:
Let w be the unknown width in centimeters. This variable is some positive real number. This means w > 0 which will be useful later.
The length is "1 cm less than 3 times its width" and it tells us the length is defined by the expression 3w-1. Whatever w is, we triple it to get 3w and then subtract 1 to get the final length.
Multiply the length and width to get the area 102
length*width = area
(3w-1)*w = 102
3w^2-w = 102
3w^2-w-102 = 0
We could guess and check our way to factoring this, but that's not very efficient. The quadratic formula is the better option. It may seem a bit messy, but it's a more direct path that doesn't involve guessing.

We ignore the second solution (w = -5.667 approximately) because we stated earlier that w > 0. In other words, a negative length does not make sense, so that's why we ignore it.
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If w = 6 cm is the width, then 3w-1 = 3*6-1 = 18-1 = 17 cm is the length.
Note that length*width = 17*6 = 102 which is the proper area we want. This confirms the answers.