Answer:
54.1° (1 dp)
Step-by-step explanation:
Let the center point of the rectangle PQRS = M
Calculate the length of the line SM using Pythagoras' Theorem:
a² + b² = c²
(11/2)² + (7/2)² = SM²
42.5 = SM²
SM = √42.5 cm
The height of the pyramid is 9 cm, therefore, MT = 9
Now we have a right angled triangle with base SM and height MT and hypotenuse ST
We want to find the angle TSM, so we can use the trig formula tan x = O/A, where x is the angle, O is MT and A is SM
tan TSM = MT/SM = 9/√42.5
TSM = arctan (9/√42.5) = 54.082088°
So the angle between the line ST and the plane PQRS = 54.1° (1 dp)
Answer:
C
Step-by-step explanation:
20+80 = 100
a triangle equals 180* so
1080-100=80 or just use a calculator OR with your brain
