Question

A circle with radii marked is inside a triangle.
▶Click for Long Desc

If △CDE
has sides that are tangent to the circle, and CF=15 cm
, BD=12 cm
, and EG=4 cm
, then what is the perimeter of △CDE
?

(1 point)
cm

Answer 1

Tangents from the same vertex to a circle are equal, so the three given segments are the three tangent-lengths from the triangle's vertices. Each side of △CDE is the sum of two of those tangent-lengths, so the perimeter is twice their sum:

Perimeter = 2(15 + 12 + 4) = 2(31) = 62 cm.