Explanation:
Let the 2 be X and Y.
Z is 3rd angle.
Z=2X
w.k.t Sum of angles in a triangle is 180°
Z+X+Y=180°
2X+90°=180°
2X=90°
=>X=45°
=>Y=90°-45°=45°
=>Z=2X=2(45°)=90°
Hope this helps you.
Answer:
age of rock is 2 million years
Explanation:

Where
is mass remaining
is original mass
n= t/t(1/2) , which is the ratio of time to half life
= 1000atoms
=250 atoms



t =t(1/2) *n
t(1/2) =1000000 years
t=1000000 *2
t=2,000,000 years