Question

The length of a picture is 10.5cm and the diagonal is 18.2cm . What width must have to meet a right angle ?

Answer 1

I decide: the length and diagonal are given. Find the width of the rectangle.

Given: a=10.5 cm; c=18.2 cm; α=90°(rectangle); b-?

------------

By T. Pythagoras

c²=a² + b²

b²=c²-a²

b=√(c²-a²)=√(c-a)(c+a)=

√(18.2 - 10.5)(18.2 + 10.5)=

√(7.7 * 28.7)=√(7*1.1 * 7*4.1)=7√4.51≈14.8657≈14.87 cm is the answer.

14cm 8.7mm.

.