A rectangular pyramid has a rectangular base and 4 triangular faces.
Short side length = x
Medium side = x + 7
Long side = 5x
Total 49, so
x + x + 7 + 5x = 49
If you combine like terms:
7x + 7 = 49
Subtract 7 from both sides
7x = 42
Divide both sides by 7
x = 6 inches
(i) Angle AOC would equal 48°, as it is vertically opposite to angle DOB and they are therefore equal.
(ii) Angle DOE would equal 42°. We can see this because angles on a straight line add up to 180°, and 90 + 48 = 138, so we can do 180 - 138 = 42°.
I hope this helps!
Area of square
= 7x7
=49
Area of triangle
=0.5x 7x12
=42
Total area of figure
=49+42
=91
Hence, answer is D

common difference is
3.6 - 5.8 = -2.2
let T1 = 5.8
T2 = 3.6
assuming we are to find T2
T2 = T(2-1) -2.2
= T1 -22
= 5.8 -2.2
= 3.6