If the tree cast a shadow of 40 feet, how tall is the tree? A. 30 feet. B.35 ft. C.40 ft. D.45 ft.

Step-by-step explanation:

This is a right triangle

Using Pythagorean theorem we can find the height:

Option A is correct

5=812a+9+3

step 1: simplify both sides of the equation.

5=812a+9+3

5=(812a)+(9+3)(combine like terms)

5=812a+12

5=812a+12

step 2: flip the equation.

812a+12=5

step 3: subtract 12 from both sides.

812a+12−12=5−12

812a=−7

step 4: divide both sides by 812.

812a /812 = -7/812

a= -1/116

so the answer is

a=   -1/116