Question

The side length of an isosceles right triangle is 7x + 3 feet. (both base and height are 7x + 3 feet).

then written in standard form, what is the area of the triangle? (area of triangle = 1/2bh)

What is the area of the triangle in cubic feet when x = 11?

Answer 1

9514 1404 393

Answer:

• area: 49/2x^2 +21x +9/2
• for x=11: 3200 ft^2

Explanation:

The area is given by the formula in the problem statement:

A = 1/2bh

A = 1/2(7x +3)(7x +3) = 1/2(49x^2 +42x +9)

The area is (49/2)x^2 +21x +9/2 . . . square feet.

__

When x=11, the area is ...

A = (1/2)(7·11 +3)^2 = 1/2(80^2) = 3200 . . . . square feet

_____

Comment on the problem statement

Area is measured in square feet, not cubic feet.