Question

Problem 4:

The hypotenuse of a right angled triangle is 20 cm. The difference between its other two sides is 4 cm. Find the length of the sides.

Answer 1

12cm and 16cm

Explanation:

The hypotenuse of the right angle triangle = 20cm

let the other two sides be x and y;

The difference;

x = y - 4

Problem:

Find x and y;

Solution:

According to the pythagoras theorem;

x² + y² = 20² ------ i

x² + y² = 400 ----- i

and x - y = 4 ---- ii

So; x = 4 + y

Now input the value into equation (i);

(y + 4)² + y² = 400

(y+4)(y+4) + y² = 400

y² + y² + 4y + 4y + 16 = 400

2y² + 8y + 16 = 400

2y² + 8y + 16 -400 = 0

2y² + 8y - 384 = 0;

y² + 4y - 192 = 0

Factorize the equation;

y² + 16y - 12y - 192 = 0

y(y + 16) - 12(y + 16) = 0

(y-12)(y + 16) = 0

y -12 = 0 or y+ 16 = 0

y = 12 or -16

It is not realistic for the length of a body to be a negative value, so y= 12;

since;

x - y = 4,

x = 4 + 12

x = 16