The developing synergy of legislation and research throughout recent history points to the current momentum behind college and career readiness for every student. Researchers have found that embedding academic content into career education improves student learning. Integrated learning can vary in approach and style and can be adjusted to fit into a multitude of environment designs. The purpose of this study was to investigate and corroborate the relationship between mathematical instructional design and student achievement. A mixed methods research design was utilized for collecting data. Qualitative data was collected from an electronic survey administered to 23 students taking a Geometry in Construction class at a Central Texas high school followed by a semi-structured interview with a focus group from the student sample. Classroom observation data was recorded from both a traditional geometry classroom and the Geometry in Construction classroom in order to provide additional insight into student perspectives related to course design. The convergent parallel design of the study included quantitative data that was collected during the same time period using pretest and posttest data sets from a traditional geometry class (control group) and the Geometry in Construction class (experimental group). Both data sets were brought together in an interpretive phase to analyze how student perceptions on learning align with student achievement scores. Results from this study revealed students who learn in an integrated learning environment where academic content is taught in a real-world context using hands-on, project-based learning perform better on academic achievement measures than do students who learn in a traditional classroom setting. While this study focused on one integrated learning model at one Central Texas high school, results indicated college and career readiness dimensions as identified by Conley (2010) are overall likely to be more naturally embedded in an instructional design geared toward rigorous and relevant knowledge application. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]