Here are two squares, A and B. A B The length of each side of square B is 4cm greater than the length of each side of square A. The area of square B is 70cm2 greater than the area of square A. Find the area of square B. Give your answer correct to 3 significant fi
Answers
Answer:
La²+8La+16 = La²+70
Step-by-step explanation:
8La+16 = 70
8La=70-16
La=54/8
La= 6.75
Area b = (6.75+4)*(6.75+4)
Area b = 10.75*10.75
Area b =115.563
Answer:
144cm²
Step-by-step explanation:
Area of square A Aa = La²
Area of square B Ab= Lb²
If the length of each side of square B is 4cm greater than the length of each side of square A, then;
Lb = La + 4 ... 1
Also if the area of square B is 70cm² greater than the area of square A, then;
Ab = Aa + 70
Since Aa = La² and Ab = Lb²
Lb² = La² + 70 ...2
Substitute 1 into 2;
(La+4)² = La²+70
Expand
La²+8La+16 = La²+80
8La+16 = 80
8La = 80 - 16
8La = 64
La = 64/8
La = 8cm
Since Lb = La + 4
Lb = 8 + 4
Lb = 12cm
Area of square B = Lb²
Area of square B = 12²
Area of square B = 144cm²