Question

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

Answer 1

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 2

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