10 x 25 = 250, well 20 x 25 is just double that, its 10 doubled x 25 so he probably just added it up. repeated addition really helps with times tables.
The value of X is D. 25
Every triangle adds up to 180 degrees so you just add up the given numbers, then subtract that number from 180 and that is your answer.
The vertical angles made is ABE and CBD, Thus meaning that your answer is B
Value of 3 is in the solution set
