sat suite question viewer
In triangle , angle is a right angle and the length of is units. If , what is the perimeter, in units, of triangle ?
Explanation
Choice B is correct. It's given that angle in triangle is a right angle. Thus, side is the leg opposite angle and side is the leg adjacent to angle . The tangent of an acute angle in a right triangle is the ratio of the length of the leg opposite the angle to the length of the leg adjacent to the angle. It follows that . It's given that and the length of side is units. Substituting for and for in the equation yields . Multiplying both sides of this equation by yields , or . Dividing both sides of this equation by yields . The length can be calculated using the Pythagorean theorem, which states that if a right triangle has legs with lengths of and and a hypotenuse with length , then . Substituting for and for in this equation yields , or . Taking the square root of both sides of this equation yields . Since the length of the hypotenuse must be positive, . Therefore, the length of is units. The perimeter of a triangle is the sum of the lengths of all sides. Thus, units, or units, is the perimeter of triangle .
Choice A is incorrect and may result from conceptual or calculation errors.
Choice C is incorrect. This would be the perimeter, in units, for a right triangle where the length of side is units, not units.
Choice D is incorrect and may result from conceptual or calculation errors.