# A right triangle has sides A, B, and C. Side A is the hypotenuse and side B is also a side of a rectangle. Sides A, C, and the side of the rectangle adjacent to side B have lengths of #18 #, #5 #, and #3 #, respectively. What is the rectangle's area?

##### 1 Answer

Apr 18, 2016

≈ 51.87 square units

#### Explanation:

The area of the rectangle

= 3BSince the triangle is right with A the hypotenuse, we can find B by using

#color(blue)" Pythagoras' theorem " #

#rArr A^2 = B^2 + C^2 rArr B^2 = A^2 - C^2# here A = 18 , C = 5

# rArr B^2 = 18^2 - 5^2 = 324 - 25 = 299# now

# B^2 = 299 rArr B = sqrt299 ≈ 17.29 # area of rectangle

#= 3B = 3xx17.29 = 51.87 #