Answer:
63
Step-by-step explanation:
Step-by-step explanation:
the side lengths of the base (the ground triangle) are equal. that means every ground side length is 8 in.
and that also makes the 3 triangles of the side areas of the pyramid equal.
so, for the surface area of the pyramid we need to calculate the area of one side area triangle, multiply it by 3 (as we have 3 side areas) and add the area of the ground triangle.
the area of a triangle is
baseline × height / 2
so, for a side area triangle we get
8 × 14 / 2 = 8×7 = 56 in²
all 3 side areas together are then
3×56 = 168 in²
the ground area triangle is then
8 × 6.9 / 2 = 4 × 6.9 = 27.6 in²
so, the total surface area of the pyramid is
168 + 27.6 = 195.6 in²
Answer:
Dimension => 10 m × 9.6 m
Step-by-step explanation:
From the question given above, the following data were obtained:
Area (A) = 96 m²
Circumference (C) = 39.2 m
Dimension =.?
Next, we shall determine the Lenght and breadth of the rectangle. This can be obtained as follow:
Let L be the Lenght
Let B be the breadth
Area of a rectangle = L × B
96 = L × B ..... (1)
Circumference of rectangle = 2(L + B)
39.2 = 2(L + B) .... (2)
From equation 2, make L the subject
39.2 = 2(L + B)
Divide both side by 2
39.2 /2 = L + B
19.6 = L + B
Rearrange
L = 19.6 – B ....(3)
Substitute the value of L in equation 3 into equation 1
96 = L × B
L = 19.6 – B
96 = (19.6 – B ) × B
Clear bracket
96 = 19.6B – B²
Rearrange
B² – 19.6B + 96 = 0
Solving by factorisation
B² – 10B – 9.6B + 96 = 0
B(B – 10) – 9.6(B – 10) = 0
(B – 9.6)(B – 10) = 0
B – 9.6 = 0 or B – 10 = 0
B = 9.6 or B = 10
Substitute the value of B into equation 3:
L = 19.6 – B
B = 9.6
L = 19.6 – 9.6
L = 10
Or
L = 19.6 – B
B = 10
L = 19.6 – 10
L = 9.6
Since the length is always longer than the breadth,
Length (L) = 10 m
Breadth (B) = 9.6 m
Finally, we shall determine the dimension of the rectangle. This can be obtained as follow:
Length (L) = 10 m
Breadth (B) = 9.6 m
Dimension =?
Dimension = L × B
Dimension = 10 m × 9.6 m
If it’s a right triangle 1 side is a right angle and if those 2 sides are equal and not right angles then E needs to be a right angle and a right angle is 90 degrees so it’s D
